Search tips
Search criteria

Results 1-10 (10)

Clipboard (0)

Select a Filter Below

Year of Publication
Document Types
1.  Modification of Akt by SUMO conjugation regulates alternative splicing and cell cycle
Cell Cycle  2013;12(19):3165-3174.
Akt/PKB is a key signaling molecule in higher eukaryotes and a crucial protein kinase in human health and disease. Phosphorylation, acetylation, and ubiquitylation have been reported as important regulatory post-translational modifications of this kinase. We describe here that Akt is modified by SUMO conjugation, and show that lysine residues 276 and 301 are the major SUMO attachment sites within this protein. We found that phosphorylation and SUMOylation of Akt appear as independent events. However, decreasing Akt SUMOylation levels severely affects the role of this kinase as a regulator of fibronectin and Bcl-x alternative splicing. Moreover, we observed that the Akt mutant (Akt E17K) found in several human tumors displays increased levels of SUMOylation and also an enhanced capacity to regulate fibronectin splicing patterns. This splicing regulatory activity is completely abolished by decreasing Akt E17K SUMO conjugation levels. Additionally, we found that SUMOylation controls Akt regulatory function at G₁/S transition during cell cycle progression. These findings reveal SUMO conjugation as a novel level of regulation for Akt activity, opening new areas of exploration related to the molecular mechanisms involved in the diverse cellular functions of this kinase.
PMCID: PMC3865012  PMID: 24013425
signal transduction; post-translational modification; SUMO; Akt/PKB; alternative splicing; cell cycle
2.  Messages Do Diffuse Faster than Messengers: Reconciling Disparate Estimates of the Morphogen Bicoid Diffusion Coefficient
PLoS Computational Biology  2014;10(6):e1003629.
The gradient of Bicoid (Bcd) is key for the establishment of the anterior-posterior axis in Drosophila embryos. The gradient properties are compatible with the SDD model in which Bcd is synthesized at the anterior pole and then diffuses into the embryo and is degraded with a characteristic time. Within this model, the Bcd diffusion coefficient is critical to set the timescale of gradient formation. This coefficient has been measured using two optical techniques, Fluorescence Recovery After Photobleaching (FRAP) and Fluorescence Correlation Spectroscopy (FCS), obtaining estimates in which the FCS value is an order of magnitude larger than the FRAP one. This discrepancy raises the following questions: which estimate is "correct''; what is the reason for the disparity; and can the SDD model explain Bcd gradient formation within the experimentally observed times? In this paper, we use a simple biophysical model in which Bcd diffuses and interacts with binding sites to show that both the FRAP and the FCS estimates may be correct and compatible with the observed timescale of gradient formation. The discrepancy arises from the fact that FCS and FRAP report on different effective (concentration dependent) diffusion coefficients, one of which describes the spreading rate of the individual Bcd molecules (the messengers) and the other one that of their concentration (the message). The latter is the one that is more relevant for the gradient establishment and is compatible with its formation within the experimentally observed times.
Author Summary
Understanding the mechanisms by which equivalent cells develop into different body parts is a fundamental question in biology. One well-studied example is the patterning along the anterior-posterior axis of Drosophila melanogaster embryos for which the spatial gradient of the protein Bicoid is determinant. The localized production of Bicoid is implicated in its inhomogeneous distribution. Diffusion then determines the time and spatial scales of the gradient as it is formed. Estimates of Bicoid diffusion coefficients made with the optical techniques, FRAP and FCS resulted in largely different values, one of which was too slow to account for the observed time of gradient formation. In this paper, we present a model in which Bicoid diffuses and interacts with binding sites so that its transport is described by a "single molecule'' and a "collective'' diffusion coefficient. The latter can be arbitrarily larger than the former coefficient and sets the rate for bulk processes such as the formation of the gradient. In this way we obtain a self-consistent picture in which the FRAP and FCS estimates are accurate and where the gradient can be established within the experimentally observed times.
PMCID: PMC4046929  PMID: 24901638
3.  Pheromone-Induced Morphogenesis Improves Osmoadaptation Capacity by Activating the HOG MAPK Pathway**
Science signaling  2013;6(272):ra26.
Environmental and internal conditions expose cells to a multiplicity of stimuli whose consequences are difficult to predict. Here, we investigate the response to mating pheromone of yeast cells adapted to high osmolarity. Events downstream of pheromone binding involve two mitogen-activated protein kinase (MAPK) cascades: the pheromone response (PR) and the cell-wall integrity response (CWI). Although these MAPK pathways share components with each and a third MAPK pathway, the high osmolarity response (HOG), they are normally only activated by distinct stimuli, a phenomenon called insulation. We found that in cells adapted to high osmolarity, PR activated the HOG pathway in a pheromone- and osmolarity- dependent manner. Activation of HOG by the PR was not due to loss of insulation, but rather a response to a reduction in internal osmolarity, which resulted from an increase in glycerol release caused by the PR. By analyzing single-cell time courses, we found that stimulation of HOG occurred in discrete bursts that coincided with the “shmooing” morphogenetic process. Activation required the polarisome, the cell wall integrity MAPK Slt2, and the aquaglyceroporin Fps1. HOG activation resulted in high glycerol turnover that improved adaptability to rapid changes in osmolarity. Our work shows how a differentiation signal can recruit a second, unrelated sensory pathway to enable responses to yeast to multiple stimuli.
PMCID: PMC3701258  PMID: 23612707
4.  Using Cell-ID 1.4 with R for Microscope-Based Cytometry
This unit describes a method for quantifying various cellular features (e.g., volume, total and subcellular fluorescence localization) from sets of microscope images of individual cells. It includes procedures for tracking cells over time. One purposefully defocused transmission image (sometimes referred to as bright-field or BF) is acquired to segment the image and locate each cell. Fluorescent images (one for each of the color channels to be analyzed) are then acquired by conventional wide-field epifluorescence or confocal microscopy. This method uses the image processing capabilities of Cell-ID (Gordon et al., 2007, as updated here) and data analysis by the statistical programming framework R (R-Development-Team, 2008), which we have supplemented with a package of routines for analyzing Cell-ID output. Both Cell-ID and the analysis package are open-source.
PMCID: PMC3485637  PMID: 23026908
image processing; fluorescence microscopy; Cell-ID; R
5.  Modulation of the Akt Pathway Reveals a Novel Link with PERK/eIF2α, which Is Relevant during Hypoxia
PLoS ONE  2013;8(7):e69668.
The unfolded protein response (UPR) and the Akt signaling pathway share several regulatory functions and have the capacity to determine cell outcome under specific conditions. However, both pathways have largely been studied independently. Here, we asked whether the Akt pathway regulates the UPR. To this end, we used a series of chemical compounds that modulate PI3K/Akt pathway and monitored the activity of the three UPR branches: PERK, IRE1 and ATF6. The antiproliferative and antiviral drug Akt-IV strongly and persistently activated all three branches of the UPR. We present evidence that activation of PERK/eIF2α requires Akt and that PERK is a direct Akt target. Chemical activation of this novel Akt/PERK pathway by Akt-IV leads to cell death, which was largely dependent on the presence of PERK and IRE1. Finally, we show that hypoxia-induced activation of eIF2α requires Akt, providing a physiologically relevant condition for the interaction between Akt and the PERK branch of the UPR. These data suggest the UPR and the Akt pathway signal to one another as a means of controlling cell fate.
PMCID: PMC3726764  PMID: 23922774
6.  Modelling reveals novel roles of two parallel signalling pathways and homeostatic feedbacks in yeast
Ensemble modelling is used to study the yeast high osmolarity glycerol (HOG) pathway, a prototype for eukaryotic mitogen-activated kinase signalling systems. The best fit model provides new insights into the function of this system, some of which are then experimentally validated.
The main mechanism for osmo-adaptation is a fast and transient non-transcriptional Hog1-mediated activation of glycerol production.The transcriptional response rather serves to maintain an increased steady-state glycerol production with low steady-state Hog1 activity after adaptation.A fast negative feedback of activated Hog1 on the upstream signalling branches serves to stabilise the adaptation response by preventing oscillatory behaviour.Two parallel redundant signalling branches elicit a more robust and swifter adaptation than a single branch alone, at least for low osmotic shock. This notion could be corroborated by dedicated measurements of single-cell volume recovery for the wild-type and single-branch mutants.
The high osmolarity glycerol (HOG) pathway in yeast serves as a prototype signalling system for eukaryotes. We used an unprecedented amount of data to parameterise 192 models capturing different hypotheses about molecular mechanisms underlying osmo-adaptation and selected a best approximating model. This model implied novel mechanisms regulating osmo-adaptation in yeast. The model suggested that (i) the main mechanism for osmo-adaptation is a fast and transient non-transcriptional Hog1-mediated activation of glycerol production, (ii) the transcriptional response serves to maintain an increased steady-state glycerol production with low steady-state Hog1 activity, and (iii) fast negative feedbacks of activated Hog1 on upstream signalling branches serves to stabilise adaptation response. The best approximating model also indicated that homoeostatic adaptive systems with two parallel redundant signalling branches show a more robust and faster response than single-branch systems. We corroborated this notion to a large extent by dedicated measurements of volume recovery in single cells. Our study also demonstrates that systematically testing a model ensemble against data has the potential to achieve a better and unbiased understanding of molecular mechanisms.
PMCID: PMC3531907  PMID: 23149687
adaptation; ensemble modeling; Hopf bifurcation; model discrimination; osmotic stress
7.  Phosphoproteomic Analysis Reveals Interconnected System-Wide Responses to Perturbations of Kinases and Phosphatases in Yeast
Science signaling  2010;3(153):rs4.
PMCID: PMC3072779  PMID: 21177495
8.  The Alpha Project, a model system for systems biology research
IET systems biology  2008;2(5):222-233.
One goal of systems biology is to understand how genome-encoded parts interact to produce quantitative phenotypes. The Alpha Project is a medium-scale, interdisciplinary systems biology effort that aims to achieve this goal by understanding fundamental quantitative behaviors of a prototypic signal transduction pathway, the yeast pheromone response system from Saccharomyces cerevisiae. The Alpha Project distinguishes itself from many other systems biology projects by studying a tightly-bounded and well-characterized system that is easily modified by genetic means, and by focusing on deep understanding of a discrete number of important and accessible quantitative behaviors. During the project, we have developed tools to measure the appropriate data and develop models at appropriate levels of detail for studying a number of these quantitative behaviors. We also have developed transportable experimental tools and conceptual frameworks for understanding other signaling systems. In particular, we have begun to interpret system behaviors and their underlying molecular mechanisms through the lens of information transmission, a principal function of signaling systems. The Alpha Project demonstrates that interdisciplinary studies that identify key quantitative behaviors and measure important quantities, in the context of well-articulated abstractions of system function and appropriate analytical frameworks, can lead to deeper biological understanding. Our experience may provide a productive template for system biology investigations of other cellular systems.
PMCID: PMC2806158  PMID: 19045818
9.  Cell-ID Software for Microscope-Based Cytometry
This unit describes a method to quantify, from sets of microscope images, various cellular parameters from individual cells, and includes procedures to track cells over time. For example, the user can measure cell volume, total and subcellular localization (nuclear, plasma membrane) of fluorescence for multiple fluorescence channels. This method uses the image processing capabilities of Cell-ID (Gordon et al., 2007) and data analysis by the statistical programming framework R, both open source software packages. The first step for successful cytometry entails acquiring at least one set of images for each field of cells. Each set is composed of one purposefully defocused transmission image (sometimes referred to as brightfield, or BF) that will be used to locate each cell, and one fluorescence image for each of the color channels to be analyzed. Images may be conventional wide-field epifluorescence or confocal microscopy images. Cell-ID processes the images and outputs a tab-delimited file with information extracted from each cell, for each time point and each fluorescence channel. Finally, the user analyzes the data using R (R-Development-Team, 2008), which we have supplemented with a package tailored to analyze Cell-ID output.
PMCID: PMC2784696  PMID: 18972382
image processing; fluorescence microscopy; Cell-ID; R
10.  Fus3 generates negative feedback that improves information transmission in yeast pheromone response
Nature  2008;456(7223):755-761.
Haploid Saccharomyces cerevisiae yeast cells use a prototypic cell signaling system to transmit information about the extracellular concentration of mating pheromone secreted by potential mating partners. The ability for cells to respond distinguishably to different pheromone concentrations depends on how much information about pheromone concentration the system can transmit. Here we show that the MAPK Fus3 mediates fast-acting negative feedback that adjusts the dose-response of downstream system response to match that of receptor-ligand binding. This “dose-response alignment”, defined by a linear relationship between receptor occupancy and downstream response, can improve the fidelity of information transmission by making downstream responses corresponding to different receptor occupancies more distinguishable and reducing amplification of stochastic noise during signal transmission. We also show that one target of the feedback is a novel signal-promoting function of the RGS protein Sst2. Our work suggests that negative feedback is a general mechanism used in signaling systems to align dose-responses and thereby increase the fidelity of information transmission.
PMCID: PMC2716709  PMID: 19079053

Results 1-10 (10)


Blog # 88 (poesie) A LITTLE NIGHT MUSIC*

The velvet cloak of Night descends,
But slower now in solstice times.
Day describes a respectful bow,
Since Dark’s far older than the Light.
Night tucks Day into its bed,
With softness and with loving care.

As if responsive to a cue,
The insect choirs take up their song
The bullfrogs croak their hoarse refrain.
Warm vapors from the day before,
Exude from all the plants and trees.

The Moon, far weaker than the sun,
Salutes the rocks with its pale rays.
Critters mostly sleep when dark,
Yet some set out in search for food.
Predators begin a nocturnal stalk;
Tall grasses dance the rhythmic breeze.

As vital is the Day to most,
I often do prefer the night
Its then I cry out to the skies,
Please, do now turn on the dark!

-p. (attributable to Leonard N. Shapiro, August, 2016)
*( title attributable to W.A. Mozart, 18th Century)

The 1980’s hit musical, “Cabaret” not only was excellent entertainment; but in addition, possessed great significance as a telling statement, a sermon on the subject of an important flaw in the human character. In the presentation, the cabaret patrons, evidently symbolizing the Berlin population, which in the 1930’s, mesmerized by the exotic entertainment,  hosted by a demonic master of ceremonies (brilliantly played by Joel Grey) were able to irresponsibly turn a blind eye and a deaf ear to the horrific Nazi atrocities( particularly against the Jews) then concurrently taking place in the streets. The flaw exemplified was the unfortunate human tendency to avoid dealing with unpleasant occurrences by looking the other way.

To come at once to the main point, it is frustrating and painful to observe that over the great many decades we have all been patrons in attendance at a real-life cabaret, averting our eyes and attention from the cruel, atavistic and barbaric atrocity that is the sport of boxing.

America was rightfully outraged and disgusted at news that a certain NFL player was engaged in the business of the public staging of brutal dogfights. He was found out, fined and suspended from play (at least for a period of time to allow our dog loving public to cool off). Cock fighting, a traditional Latino event, as well as all bloody animal contests are illegal; a federal statute makes it no less than a felony, punishable up to five years in prison plus a fine of $250,000. It is well known that there are several agencies and foundations established to prevent cruelty to animals, such as the ASPCA, PETA and, WWF. (See: Blog # 37) .Movies that use animal actors uniformly display a notice, together with the film credits, that no animal was mistreated in the production of the film as an assurance to the moviegoer.

The controversial subject of school sport injuries, especially concussions, is gaining ever increasing attention. Concussions, we are advised, are incurred either by a significant blow to the head or by the cumulative repetition of lesser blows. Customized helmets are being developed in an attempt to lessen the occurrence of concussions in football and other contact sports. In some jurisdictions, the wearing of a protective helmet is mandatory for motorcycle and bicycle riders. It should be noted that there is a great deal of ongoing and heated debate concerning the issue of eliminating football and other contact sports altogether from school, notably, high school.

In fairness, it must be noted that football is not a “blood sport.”  The theme of the sport is to earn goals and not to cause injury.  However, the all too frequent collateral injuries during football play, provide  many a cogent rationalization for the banning of the sport.

In this context, what does the legally approved activity of boxing (and even worse, cage fighting) reveal about the nature of our civilized society? In ancient Rome, considered a brutish society, unfortunate gladiators (often slaves or prisoners) engaged in deadly combat for their life, for the primitive amusement of the bloodthirsty spectators. This barbaric travesty went so far as to feature, historians reveal, deadly combat between dwarfs and women for public entertainment.

Unlike football, where injuries are unintended and are collateral to the play, the express, sole theme of boxing is the causation of disabling injury to the opponent. The more lethal the punch, the more points are awarded by referees, avid and enthusiastic experts in discerning high scoring serious injury. Ultimate success is attained by rendering the opponent unconscious, the ultimate act of victory; usually met with howls of approval from a highly stimulated audience. We are not professionally competent to diagnose the mental and physical health of professional boxers over the course of their career, but it is safe to expect that it is not salutary.

For some time, and presumably, for the foreseeable future, we all seem to be patrons of our American cabaret and look the other way. Perhaps the contrasting interest in school sport injuries may be explainable by the fact that the young players are identifiable, often our own children.

What quality of compassion, sanity and wisdom do we evince by expressly and properly outlawing cruelty to roosters and dogs and simultaneously providing  legal status and societal permission to this immoral travesty regarding humans?

Willkommen zum Kabaret

For illustrative purposes, we will, initially, conjure up the following bit of fiction.

A 29 year old white mother is escorting her five year old daughter to school; they are walking at a slow pace, hand in hand. The mother, a Barnard College graduate (in American Studies) is a well- educated, forward  thinking person and an ardent supporter of civil rights, donating annually to the NAACP and the Urban League, and an outspoken opponent of racial prejudice .They notice another young mother, who it happens, is black, similarly accompanying her young child to school. The white mother’s  little daughter feels a very subtle squeeze of her hand, an act, virtually unconscious, of which her mother would be completely mortified if she were made aware of it; the explanation for this dynamic is no less than the fundamental and universal basis for all racial and ethnic prejudice.

Historians will readily identify past episodes of strife and injustice and suggest that such events are the root causes of today’s many ills, offering factual accounts which underlay their theories; we do emphatically disagree.

The horrible bloodshed between Sunni and Shia Muslims as they say, can be traced back to a 7th Century dispute as to the proper method of succession to Prophet Mohammad, either by familial inheritance or by democratic vote. The Greek-Turkish enmity, historians say, dates back to the military defeat of Greece by the Ottoman forces, under Kemal Ataturk. The Irish-English conflicts are fueled by past wars concerning religion and economics; the Protestant-Catholic troubles including the 30 year’s war dating back to Luther. Anti-Semitism, they will tell you is rooted in the scandalous claim that the Jews were responsible for the death of Jesus. These may, in general, be rather accurate depictions of historical events but are, in reality, not at all the dynamic basis for bigotry and prejudice in our modern times.

To our point, as we have previously stated, it is only by the random accident of birth that we acquire our respective features, culture and belief systems. Some, undoubtedly well intentioned parent or other adult soon sows the pernicious seed of “we” and “they” (perhaps to give the child a sense of belonging) in the fertile and imaginative mind of the young person. From such unfortunate implantation, thereafter mythologies about the “other” are created, perhaps then evangelistic inclinations and thereafter, conflict and war. This problem is fundamental and timeless and not founded upon the recalled horrors of the past (undoubtedly due to similar causes). We must consciously and effectively amend our messages to our young concerning “we” and “they” and find a way to inculcate a more appropriate consciousness of an “us” and a respect and appreciation for diversity. Others may have differing belief systems and sometimes even look a little different from us but the young must be taught that we are all life tenants on the planet. This will take generations, much to the justified dismay and impatience of those who are the victims of discrimination, but it seems to be the only effective and enduring way. In the interim, we certainly can be good neighbors and friends to each other

The mother, unaware that she subtly squeezed her daughter’s hand is a good person, but undoubtedly a product of an early “we” “they” upbringing; the daughter is now, unfortunately, another.       –p.

The eminent British philosopher, John Locke, an empiricist, maintained that man is born with a blank slate, to be inscribed by him with knowledge acquired from experience.

Those who choose to avail themselves of the sheer joy and profound experience of reading great literature, thereby acquire an in-depth understanding of the phenomenon of life, its potential and its challenges, and are empowered to relate such understanding to their own experience.

One can comfortably sit at his favorite perch, armed only with a small light and a great book and, while sedentary, travel the planet and the cosmos; he can acquire enlightenment and valuable insight to himself and others by examining other lives and life situations as created and aesthetically portrayed by the great authors. A certain valuable category of books are labeled “Classics” since they portray man’s eternal plight on the human canvas. These exceptional works should be read and re-read (“reprised”) not only as a continuing source of great pleasure, but as instructive and comforting insight and perspective into the timeless, universally eternal issues which are implicit in the human condition.

The young adult, albeit in possession of the requisite intellectual and aesthetic ability to comprehend and enjoy such literary works, nonetheless, is at a relatively prerequisite stage of maturity and potential development ; his future course of life will instruct him, experientially and developmentally, in levels of ever  increasing sophisticated insight. This maturity will lead him, ultimately, to the fuller appreciation and comprehension of the author’s intended message.

The mature reader, with a lifetime of accumulated experience, has thus acquired the in- depth capacity to identify with the life and characters portrayed and is equipped to appreciate the full extent of  the author’s message and intention; his own  experiences, joyous and tragic,  empowers him with the ability to spiritually identify and  communicate with the classical author.

Reprising the great classics of literature at a later stage of life is a satisfying life-enhancing experience .A little dust never hurt anyone.

Blog # 84         OUR PLANET SPEAKS…

A  possible theory which might explain the difference between the plethora of writings seeking the abolition of the death penalty, as compared with a relative dearth of the same in favor of its continuance. It may be suggested that the arguments in its opposition are essentially based upon rational premises and therefore readily amenable to their literate expression, while the contrary position is not.

There are but few enlightened, democratic countries (unfortunately, including the U.S.) that still feature the atavistic and barbaric practice of the death penalty. It would seem far more emblematic of theocracies and other tyrannical regimes which have need of it to intimidate and control their respective populations.

Many logical and ethical arguments have been repeatedly made in opposition to the death penalty and it would seem sufficient merely to refer to them:

It is cruel, barbaric and antithetical to an enlightened society,
It has completely failed to serve as a deterrent,
It is grossly unfair in its racial application,
Following execution, mistakes in justice cannot be rectified,
Legal defense provided for the indigent defendant has been inadequate,
Its application has been unacceptably arbitrary,
It has proven by experience to be unfair to the mentally handicapped,
Its administration has often been incompetent causing horrific suffering,
It violates Natural Law (as stated by many eminent philosophers, including John Stuart Mill),
The long period between sentence and execution is great torture, and,
It is illegal under the U.S, Constitution’s prohibition of “cruel and unusual punishments.”

These are the cogent arguments seeking the abolition of the death penalty which have been eternally made and, as stated above, there would seem to be no utility in their restatement. It is telling, however, to point to the historic and expressive nature of the words, “capital punishment, themselves. The significant word, “capital” is directly referable to the identical verb origin as “decapitate” as used in such societal niceties as the guillotine and the chopping block (capital means “head”). The other euphemistic word is “execution,” referring to action such as, execution of a policy, a plan, the execution of an act. The employment of such banal euphemism is an admission of the undeniable, express and defensive recognition of the practice as a gross moral atrocity.

A related topic may be the “Right to Life” organization and its over- zealous adherents, whose dedication is antithetical to its pirated name. Their sole purported goal is the protection of the fetus, in contrast to their actual goal, the denial of a mother’s right to an abortion. This cohort claims religion and ethics as their basis, but would, after the birth of the fetus, deny the poor child needed help, including food stamps, affordable health care, welfare or any other program of vital assistance. After the event of birth, their religion and morality seem to become non-existent. These so- called “right to lifers” have strategically committed premeditated murder of abortion providers, favor the free sale and distribution of guns, are supporters of the subject death penalty and seem to consistently advocate military action in preference to diplomacy in instances of international problems. This is all shamefully abhorrent to its misleading name. (See Blog #52).

We would give expression to what appears to the sensitive observer, the subtle but articulated, concern for the continuation and preservation of “life” meaningfully expressed by our Planet in countless observable ways. The dynamics of planetary evolution over the countless millennia toward a sentient being, the self- healing of trees after a violent storm, the rebirth and replacement of flora following forest fires, the ingenious tactical dispersion of seeds by plants, are but a few examples of the seemingly infinite instances of a clear-cut planetary message that life’s continuance is mandated.

This (no less than) imperial mandate of Nature is certainly not within the jurisdiction of any legislature, however august, nor capable of refutation by the ignorant and misguided advocates for” justice” (read “vengeance”). The horrific approved murder of individuals guilty of murder creates an undesirable equivalency and inconsistency from the standpoint of any professed civilized and humane society.

Incidentally, what is being” killed” when a criminal’s (or any other) life is terminated? After death the body becomes completely useless and disposable; is it some species of electro-chemical power that is switched off when certain body parts are destroyed? The profound mystery of life and death ought not to be tampered with by the ignorant and unaware.

Every living thing is the recipient of a generous planetary franchise: to function. Our current initiation of major programs to probe deep outer space, are all in essence, a search for other “life.” We must be ever aware that (no less than) our own Planet, through its communicated phenomena of Nature, demands that the gifted franchise of life is eternally to be gratefully maintained and nurtured.

Blog # 83 (poesie) PANTHEIST SABBATH

Cool Connecticut morning
Bees buzzing the big hydrangea
Wings flapping at pendant feeders
Mental kisses to scampering chipmunks
I blink at the leafy sunshine-
Dare not miss the Sabbath devotion
Forest woodland the iconostasis
Choir sounds from green bushes
Floral gifts from Nature’s rosary
Holiness high up the treetops
Resurrection in the sprouting soil.

Could man but reject his idols
And their belligerent servitude,
All would be Connecticut morning
Bees a-buzz and wings a- flap, for ‘ere.

.p- (attributed to Leonard N. Shapiro, August 2016)

Spoken words are the expressed formulation of the speaker’s thoughts. Those fortunate to be gifted with the skill to do so precisely have a greater likelihood of meaningful conversation. Spoken words stimulate a response on the part of the listener who, hopefully, is objective enough to apprehend the speaker’s meaning and intention. As noted previously (Blog#81), the optimum interaction is one in which all participants are consistently dedicated to the identical subject.
Ethically and solicitously, the speaker should earnestly strive to maintain an awareness and sensitivity to the likely effect of his words upon the other party and not thoughtlessly speak merely to discharge the personal energy of a presenting thought.
Ideally therefore, the parties would adhere to the same subject and context and maintain a conversation in the nature of a spontaneous exchange of thoughts on a common subject; this is all too often not the case. Too many conversations take place between parties who pay little, or no attention, to the specific subject and engage in the formal “dance” of a conversation as occurs in the automatic exchange of a handshake.
There are particular instances in which the choice of vocabulary has the potential to evoke an emotional response on another, in contrast to those exchanged in meaningless banter.
In this brief note, we specifically exclude the subject of verbal exchange in the romantic context. In any case, most participants, particularly of the female gender, it seems, are well schooled in the impactful significance of such words as, “love,” “commitment,” “relationship,” “intended,” and the like. Most of such words are accorded an exalted status, above mere vocabulary, and enjoy the experienced status of a professionally competent diagnosis of the presenting facts.
In other contexts, the use of certain words have profound impact, examples are,” love,” “ hate,” “fear,” “peace,” ”friend,” “trouble,” and many, many more. We would however, limit the scope of this note to two words, “probability” and “possibility.” These concern distinctly different predictive words which when used appropriately, summon markedly different reactions.
“Probability,” in general, means likely to occur or is expected, i.e., a frequently experienced result. It is a mildly qualified expression concerned with empirical experience, percentage outcome, deductive or inductive reason. It is because it is empirical, and therefore, measurable, that there exists an entire discipline in mathematics devoted to the calculation of probable outcomes; the algebraic calculation of probability results in a statement of the percentage likelihood of occurrence of the selected event or result.
“Possibility,” by contrast, connotes the occasional chance of occurrence (as opposed to its expectation, as in “probability). It is more ethereal and theoretical, a prospect which in the future may attain realization. It is not predictive in the same way as probability and therefore not readily capable of calculation. The possibility that an asteroid may collide with our planet is a matter of some scientific interest; a probability of such occurrence would justify global panic. Significantly, in the area of medical illness, the predictability, or probability of full recovery would evoke a feeling of relief; a statement of the possibility of recovery would encourage concern. In all factually important instances of any kind, the competent observer should be scrupulously assiduous in the selection of the appropriate description of the degree of realistic expectation.
We would offer some comments regarding the appropriate and sensitive use of these two expectancy words in the hope that they may be of some interest:
1. In matters of illness or temporary disability, if possible and accurate, speak in the context of predictability or possibility. A demonstration of advance knowledge by the recitation of remote possibilities may cause unnecessary anxiety. That an individual might conceivably, pull out a nose hair, resulting in a fatal toxicity, is somewhat possible, but not at all probable.
2. Words connoting probability are preferable with regard to the initiation of new business ventures. The mere “possibility” of success would seem remote and not encouraging.
3. The probability that she (he) loves me back is a far better prospect than such possibility.
4. In general, the possibility of failure should not inhibit the new entrepreneur, the start of a scientific inquiry or an aspiration for the love of another person.
There are, indeed, many possibilities whose contemplation are positive and hopeful; the possibility of enduring world peace, the possibility of finding a unified cure for cancer, the possibility of real and lasting brotherhood, the possibility of a clean and green planet. May we dare to hope that these possibilities evolve into probabilities and eventually to the reality?


We all instinctively recognise symmetry when we see it, but describing it in words is harder than you might think.

Make your own climate prediction with this simple, but powerful, model!

An insightful look at the climate models that predict our future.

Our messy desk is proof of the second law of thermodynamics...

Why the expected outcome of rolling a die is 3.5.

Some general ideas in very few words and without equations.

Why did physicists at the beginning of the 20th century feel they needed a new — and strange — theory?


10/21/2016 to 10/23/2016
Jeff Carreira

The Practice of No Problem is a simple yet profoundly effective form of meditation. With this practice, you learn to embrace life as it already is rather than struggle against it.

10/21/2016 to 10/23/2016
Dzogchen Ponlop Rinpoche
A Buddhist Approach to Finding Strength Through Right Action

Suffering is inevitable in life—we all encounter it. But how we respond to it can be the difference between more suffering and happiness.

10/21/2016 to 10/23/2016
A Journey Into Asana, Meditation & Pranayama

Yoga has long been recognized as a spiritual and physical journey to experience life directly and be at peace.

10/21/2016 to 10/23/2016
Michael Bernard Beckwith
Evolutionary Technology for Finding Your Highest Purpose

How will you use this singular treasure of life that you have been given? What is the purpose of the unique blend of skills, gifts, experiences, and perspectives that you alone possess?

10/21/2016 to 10/23/2016
Nicolas David Ngan
Creating Bliss in Your Everyday Life

Hidden inside your birth name is a blueprint for living a more blissful life. Unlock the truth of your Soul Contract and release your full potential with this ancient system of numerology.

10/21/2016 to 10/23/2016
Sil Reynolds


Web Results

Optical microscope

The optical microscope, often referred to as light microscope, is a type of microscope which ..... The optical components of a modern microscope are very complex and for a microscope to work well, t...

How Light Microscopes Work | HowStuffWorks

The human eye misses a lot -- enter the incredible world of the microscopic! Explore how a light microscope works.

How does a light microscope work? | Reference.com

A light microscope uses a focused beam of visible light to magnify objects for observation. It works in a similar way as a refracting telescope but with several ...

The Compound Light Microscope

How it works: Compound Light Microscope: The microscope pictured above is referred to as a compound light microscope. The term light refers to the method by ...

www.ask.com/youtube?q=Light Microscopes Work&v=FvTrWridZss
Feb 9, 2012 ... Physics - Optics: Optical Instruments (3 of 3) The Microscope - Duration: ... How To Use a Compound Light Microscope: Biology Lab Tutorial ...

How does a Microscope work ? - Best Microscope Home

Understanding these ideas is the first step to learning how a microscope works. The optical or light microscope uses visible light transmitted through, refracted ...

Optical Microscope - How Optical Microscopes Works?

Focusing Light in an Optical Microscope ... The Nikon AZ100 Multizoom Microscope - Combining ...

How Does An Optical Microscope Work | DK Find Out

Optical microscopes, also called light microscopes, are the most commonly used type of microscope. Most optical microscopes are compound microscopes, ...

Compound Light Microscope: How It Works - Bright Field Microscope

To comprehend how the compound light microscope (also called a "bright field" microscope) works we must first understand that convex lenses bend light rays ...

Light microscopy - Rice University

More Info

The Basics - How Light Microscopes Work | HowStuffWorks

The Basics - The human eye misses a lot -- enter the incredible world of the microscopic! Explore how a light microscope works.

How does a microscope work? - Explain that Stuff

Jul 17, 2016 ... Powerful microscopes shed new light on the teeny tiny and make the invisible, visible. They've played an enormous part in science by taking us ...

Microscope World Blog: How Does a Light Microscope Work?

May 18, 2015 ... Info on how a light microscope works and the different features and functions of the compound microscope.


It doesn't have to rhyme and there's no set formula. This poetry class is about as far away from Roses are Red as you can get.

For the last few weeks students at St. Frances Elementary School in Saskatoon have been sitting down to write poetry with spoken word artists.

The project was to create pieces of poetry about their history, culture and Cree language.

A big part of this project is performance. At first, students were to shy to share their poems.

"They would get the Facilitators to read it for them," explained project co-ordinator Desiree Macauley. "Since then, I've seen tremendous growth. They went from that to standing up and reading in front of the class. That's a huge accomplishment!"

It goes beyond the confidence to perform. The students say poetry has also given them a chance to vent about their lives and deal with problems.

"It helped me get my anger out." Madison Pahtayken said, "It helps me take it out of my mind and body and get it onto paper. Then I can either crumple that paper up and throw it away or share it."

Jordan Schultz is a spoken word artist in Saskatoon. He said poetry gives young people a voice and another option.

It gives them "the idea that they can use something so simple as the spoken word and create beautiful pieces, express themselves and use it as a teaching tool," Schultz explained.

A few of the students will be making their big debut Wednesday night. They will be featured performers at the Oskayak High School Gala at the Broadway Theatre.


Curiosity Lands on Mars, Sends First Picture in Minutes

In a much anticipated event, the most advanced Mars rover touched down on the red planet's surface on Sunday at 10:32 PM PST, one minute behind schedule and only 2.27 miles from the targeted location inside the Gale Crater. It was a landing of stunning precision, given the fact that the signal sent by the equipment takes 14 minutes to reach Earth, which means that, by the time NASA and the member of the Jet Propulsion Lab received confirmation of the beginning of the seven-minute landing process, Curiosity had successfully landed seven minutes before that and began sending data and first images, which reached NASA at 10:34 PM PST.

In a live feed shown on NASA's page, people around the world followed the landing and it appeared to be taking place exactly as planned.

"The Seven Minutes of Terror has turned into the Seven Minutes of Triumph," said NASA Associate Administrator for Science John Grunsfeld in a prepared statement. "My immense joy in the success of this mission is matched only by overwhelming pride I feel for the women and men of the mission's team."

In fact, it was a much needed success for cash-strapped NASA, which is celebrating an immense success and gain in prestige. President Barack Obama previously set the goal for humans to be sent to Mars by 2030 and much more advanced landing of Curiosity, which included several phases of descent and slowdowns of the capsule and its car-sized rover, lend confidence that this goal is realistic and achievable.

At this time, NASA is evaluating Curiosity's instruments and is analyzing the landing site. There are ten instruments on board that have 15 times the mass of the instruments of the payload previously carried by the now immobile Mars rovers Spirit and Opportunity, which landed on January 4 and January 25, 2004. Curiosity is about twice as long and five times as massive as the Spirit and Opportunity Mars exploration rovers. It weighs 1,982 lbs and is 9.8 ft in length. It can pass obstacles up to 30 inches in height and will travel at an anticipated average speed of 98 ft per hour.

Its power is derived from a radioisotope thermoelectric generator (RTG), similar to the one used by the Viking 1 and Viking 2 Mars landers in 1976. The power output is 125 watts of electrical power extracted from about 2000 watts of thermal power, which will gradually decrease as the plutonium-238 decays over time. Scientists estimate that there will be about 100 watts of electrical power left in about 14 years. Curiosity can generate about 2.5 kWh per day, in comparison to only 0.6 kWh the smaller Spirit and Opportunity had available.

Contact Us for News Tips, Corrections and Feedback


, Volume 51, Issue 3, pp 395–406

Existence and Non-existence in Sabzawari’s Ontology

    • Asia InstituteThe University of Melbourne

DOI: 10.1007/s11841-011-0283-z

Cite this article as:
Kamal, M. SOPHIA (2012) 51: 395. doi:10.1007/s11841-011-0283-z

Sabzawari is one of the greatest Muslim philosophers of the nineteenth century. He belongs to Sadrian Existentialism, which became a dominant philosophical tradition during the Qajar dynasty in Iran. This paper critically analyses Sabzawari’s ontological discussion on the dichotomy of existence and quiddity and the relation between existence and non-existence. It argues against Sabzawari by advocating the idea that ‘Existence’ rather than quiddity is the ground for identity as well as for diversity, and that non-existence, like existence, is able to produce an effect.

ExistenceNon-existencePrincipality of existencePrincipality of essenceQuiddityPredicablesIdentity in differenceBecomingOntologyIntuitionMystic experience

Mulla Hadi Sabzawari (1797–1878) is a profound Muslim philosopher who lived during the Qajar dynasty in Iran. He developed his ideas under the influence of Mulla Sadra’s Existentialism. He wrote a number of books; among them is Sharh-i munzumah (Commentary on a philosophical poem), where he discusses different ontological issues and reflects on the meaning of ‘Existence’. Among these ontological issues the dichotomy of existence and quiddity and the relation between existence and non-existence, and Sabzawari’s analysis of them, are the subject of this article. I wish to criticise his views and argue against Sabzawari that ‘Existence’ rather than quiddity is the ground for identity as well as for diversity, and that non-existence, or the non-presence of existence like existence, is able to produce an effect.

Understanding Sabzawari’s analysis of these two ontological issues is not possible without reference to his intellectual background, in particular, his Sadrian Existentialism. This stood in opposition to Suhrawardi’s Essentialism, which advocated the doctrine of the principality of ‘Essence’ (and dominated the philosophical school in Isfahan during the Safavid dynasty). For Suhrawardi ‘Essence’ is the reality of everything. Something exists when its essence is manifest and known. Its existence is totally dependent on its essence. Besides, Suhrawardi argues that ‘existence’ is a concept that does not correspond to anything outside thinking.1 Mulla Sadra brought about a fundamental philosophical change by thinking ‘Being’ rather than ‘Essence’ as the sole reality. In this regard, and for the place of Mulla Sadra in history of Muslim philosophy, Seyyed Hossein Nasr states that ‘he founded a new intellectual school in Islam, which means that he was able to open up a new perspective’.2 This new perspective is inaugurated with a kind of ontology, in which ‘Being’ rather than ‘Essence’ is seen as the sole reality and the ground on which all beings stand.3 He also believes that ‘Being’ manifests itself in different modes. Every mode has a unique way of existence and is a grade of ‘Being’. The self-manifestation of ‘Being’ is called ‘gradation’, which gives rise to the realm of diversity where all beings undergo constant substantial and accidental changes in order to achieve perfection.4 Mulla Sadra’s ideas had a significant impact on the development of philosophy in Persia, not immediately after his death in 1640 but later, in the Qajar period.5 During that time, a philosophical school was established in Tehran, and Mulla Hadi Sabzawari emerged as one of the profound Sadrian philosophers, and the founder of a school in Khurasan.6

Using as his basis the complex ontological and epistemological structure of Mulla Sadra’s philosophy, Sabzawari revived the principality of ‘Existence’ and incorporated mystical knowledge into rationalistic discourse. For Sabzawari, reason is incapable of accessing the truth of ‘Existence’, which resists definition and description. In order to avoid a negative conclusion concerning our knowledge of ‘Existence’, it is necessary to search for a cognitive tool other than reason that is capable of apprehending the truth of ‘Existence’. Mulla Sadra, before Sabzawari, found that new cognitive tool and came to the belief that the truth of ‘Existence’ could be known in the mystic experience rather than in rationalistic discourse: ‘The knowledge of the reality of existence cannot be except through the illuminative presence and an intuition of the [immediate] determined [reality]; then there will be no doubt about its inner-nature’.7 For Mulla Sadra it followed that the only way to understand the truth of ‘Existence’ is through mystic experience. The problem of this cognitive tool was that not every individual is able to possess it; it is a spiritual capacity obtained and developed by the seekers of truth on the mystic path. The illuminative presence resembles the vision of the true philosophers in Plato’s Republic who obtain knowledge of the universal forms and finally of agathon the universal form of Good. For Plato, not every individual is capable of acquiring this knowledge as it is conditioned by self-emancipation from the dogma of the cave and reaching out to the source of light. This self-emancipation is seen as a philosophical task and the prerogative of a small number of individuals known as philosophers.8 The questions that arise here are: What is this peculiar nature of ‘Existence’? Why are we unable to access it rationally? If ‘Existence’ is the sole reality then can we think of the possibility of ‘non-existence’?

In opposing Suhrawardi’s doctrine of the principality of ‘Essence’, Sabzawari expresses his agreement with Mulla Sadra, stating, ‘In fact, (the philosophers) have been divided by upholding two theories. The first asserts that the principle of the realization of anything is “existence” while “quiddity” is merely something posited, i.e., a mental counterpart to “existence” that is united with the latter. This is the doctrine held by the most authoritative of the Peripatetics. And this is also the doctrine chosen here, as is indicated by the following verse: “Existence, in our opinion is fundamentally real”.9 Existence rather than essence is the sole reality and the ground for all ‘existents’. It constitutes the reality in every concrete existent. Every existent in itself is an individual case of ‘Existence’. It should be remembered that the relationship between ‘Existence’ and its own modes is not like the relationship between universals and particulars, simply because ‘Existence’ is not a universal concept like ‘blackness’ but the reality and an ontological ground on which everything stands. Described in this way, the ontological difference becomes essential for understanding the meaning of ‘Existence’ and determines its nature. It is possible to apprehend an existent, yet our knowledge of it will not guarantee accessibility to ‘Existence’. In rationalistic discourse, an existent is seen as a polarized entity and is analyzed into existence and quiddity, but this is not the case with ‘Existence’. ‘Existence’ cannot be conceptualized and quiddity be affixed to it. Meanwhile, it is self-evident and cannot be reduced to anything: ‘Its notion is one of the best-known things, but its deepest reality is in the extremity of hiddenness’.10 The self-evidence of ‘Existence’ is based on its nature as something simple and intuitively apprehended without mediation or representation. Yet, its reality is concealed and we are not able to grasp its truth. We know what the term ‘existence’ means but this does not assist us to understand the reality of ‘Existence’ as they are different and not the same. We talk about the existence of a tree, for example, while ‘Existence’ as such is beyond it. We find ourselves confronted with the enigma of understanding the truth of ‘Existence’ since its reality is transcendental and defies definition and description.

The inaccessibility of the truth of ‘Existence’ advocated by Sabzawari is based on Mulla Sadra’s interpretation of the meaning of ‘Existence’ in his major philosophical works, such as al-Asfar, a magnum opus that contains his entire philosophical system, and al-Masha’ir. Mulla Sadra holds the view that since ‘Existence’ has neither genus nor differentia it does not have a definition.11 A definition is applicable to the particular existents or to concrete instances with genus and differentia; it relies totally on the presence of these universal determinations. Whatever is defined should belong to a genus and have differences that distinguish it from other members of the same genus. Sabzawari emphasizes this by saying, ‘So, they, i.e., all (so-called) definitions, can neither be a “definition” in view of the fact that “existence” is (absolutely) simple, having neither specific difference nor genus, as we shall see presently; nor can it be a “description” because a “description” is obtainable only by an accidental property, which is part of the five universals whose division itself is based on the thing-ness of “quiddity”, while existence and its properties derive from an entirely different source from “quiddity”.10 It is worth mentioning also Mulla Sadra’s and Sabzawari’s view on this resembles that of Martin Heidegger, a Western thinker who maintained that ‘Existence’ is indefinable for the same reason. Heidegger commences his analysis in Being andTime (1927) with a discussion of three prejudices that arose in Western philosophy from the time of Plato against any inquiry into the meaning of ‘Existence’, and which led to the oblivion or ‘nothing-ness’ of ‘Existence’ as a philosophical standpoint and gave rise to metaphysical thinking and nihilism in the West. The three prejudices are: (i) existence is the most universal concept; (ii) it is indefinable; (iii) it is self-evident. Heidegger is in agreement with Mulla Sadra and Sabzawari in stating that ‘Existence’ is neither a concept nor a genus. Its universality encompasses the universality of every genus.12 Two factors support this claim that ‘Existence’ is indefinable: the first is related to the nature of ‘Existence’ as something simple; the second is a limitation in the traditional logic for defining ‘Existence’. These two factors become obstacles to any attempt to define ‘Existence’ because ‘Existence’ has no genus and is not a member of a higher class. Its simplicity and universality are unlike anything else.

Describing ‘Existence’, like defining it, is also doomed to failure. Description is possible in the presence of universal predicables, such as genus, species, difference, property and contingent accidents, but ‘Existence’ has no predicable.13 One may attempt to apply these predicables in an attempt to give quiddity to ‘Existence’, making it compound and mixed, but ‘Existence’ is simple and has no quiddity. If quiddity is assigned to ‘Existence’, then quiddity becomes an addition to it.14 In that case, ‘Existence’ will suffer division, presuppose its own parts, and be unable to become a unitary ground and apriori principle for the multiplicity of things. By contrast, the concrete existents are multiple and different in one way or another. Animals, for example, are not plants, yet they share existence. Existence is an ontological ground not only for the presence of the existents in the world, but also for their unity: ‘If we adopt the view that it is “existence” that is fundamentally real we would recognise that here, running through all the scattered “quiddities”, is one single reality (i.e., “existence”). This is comparable to the unity that we observe in things having extensions, whether they be immobile or mobile, for their multiplicity is mere potential, not actual’.15 What makes them different from one another are the universal determinations assigned to them in thinking. These universal determinations are conceptual and not real. ‘Existence’, rather than these universal determinations or quiddity, guarantees the actual presence of the existents in the world, and is one and the same in all of them. The unmixed nature of ‘Existence’, which becomes a ground for the principle of identity or sameness, is the reality of every existent. At the same time, whatever is existent and present in the world has a quiddity, and can be analysed intellectually into universal determinations. Here, according to Sabzawari, the dichotomy of existence and quiddity is a product of thinking. Sabzawari is also critical of Muslim thinkers who believe that existence is added to quiddity mentally. He developed four arguments to justify his criticism. In his first argument he stated that existence and not quiddity is properly negated. For that reason, existence is neither the same as quiddity nor a part of it.16 Sabzawari’s second argument is based on Ibn Sina’s view that the predication of quiddity by existence requires a middle term; it needs ‘what is accompanied by “because”’. The reason for this goes back to the nature of predication. The truth of some propositions, such as ‘intellect is existent’, requires a proof. By contrast, the predication of quiddity and its essential properties does not require any proof because it is self-evident.17 The third argument is related to the distinction between existence and quiddity in thinking through rational analysis. We rationalise the quiddity of something, for example a triangle, without regarding its external existence. In doing so we realise that ‘what is not disregarded is other that what is disregarded’. This will make existence something that occurs to quiddity.17 This also indicates that existence is neither the same as quiddity nor a part of it. The fourth argument states that if we think of existence as the same as quiddity or a part of it, then quiddity will need another existent because it is impossible for an ‘existent’ to be constituted by ‘non-existence’. As a consequence of this, ‘existence’ will become a part of a part and so on to infinity.18 As we see, Sabzawari has developed these arguments for the principality of ‘Existence’ and believes that ‘Existence’ is the unity, while multiplicity or diversity in the world is due to our apprehension of quiddity. This happens when the possible beings are conceptually analysed into the universal determinations. Whatever is found in the world is then the combination of existence and quiddity (zawj tarkibi). The latter is that by which each possible being is differentiated from all others. The quiddity of a horse, for example, is different from the quiddity of a table. Toshihiko Izutsu also confirms this kind of duality and states that ‘This fundamental fact about the two ontological factors is what Sabzawari refers to when he says that “existence” is the principle of unity, while “quiddities” raise only the dust of multiplicity’.18 He states clearly that quiddity, unlike existence, has given rise to diversity in the world. Existence determines the identity of all existents while quiddity becomes the source of their differences: ‘If “existence” were not fundamentally real there would be no unity actualised, because all other things raise only the dust of multiplicity’.19 Here, ‘all other things’ with the characteristic of multiplicity are quiddities of the existents. This distinction between identity and difference is the outcome of the ontological dichotomy of existence and quiddity in the realm of ‘Becoming’, for the reason that, as mentioned earlier, ‘Existence’ does not have quiddity. The unity of existence in intuition is accompanied by diversity assigned to the existents in thinking. Here, the problem is not whether this dichotomy is real or not. The question is concerned about the genesis of diversity. It is important to know whether ‘quiddity’ becomes an ontological ground for diversity or not.

The distinction between existence and quiddity is not found through intuition, for whatever is experienced in intuition is an existent and not quiddity. Quiddity is the product of the rationalistic analysis of an existent into universal determinations. These universal determinations are conceptual and have no reality of their own outside the domain of the human mind. Quiddity, in this way, remains in thinking and will never see the light of day. There will be no distinction between existence and quiddity in the external world and will have no ontological reality. Whatever is real and apprehended is existence. When we look at the non-ontological position of quiddity as something unreal, and if this unreality becomes the foundation for diversity, then diversity becomes fictitious. How can something unreal (not existent) become an ontological ground for diversity in the world? Quiddity corresponds to nothing outside thinking. It is unthinkable by itself without being attached to an existent in mind. By contrast, an existence stands by itself and does not depend on quiddity to sustain it. When we analyse an existent into universal determinations in order to grasp its quiddity, we counter nothing in the external world to represent it except an existent. All universal determinations are mere concepts. Their application is also intellectual. The reality, which is present to our experience, is an existent, a mode of ‘Existence’ in a concrete form, not quiddity. Up to this point our analysis has not contradicted Sabzawari’s, but a problem arises when the genesis of diversity is investigated and its reality is examined.

In my opinion, the principality of ‘Existence’ is all-embracing. All distinctions and all diversity are but apparent facets of the reality of ‘Existence’. Diversity is nothing more than the process of self-gradation of ‘Existence’ (tashkik al-wujud), in which ‘Existence’ manifests itself in a number of ways and gives rise to multiplicity. The difference between the multiple modes of ‘Existence’ is not inherited from quiddity in thinking but in the degree of intensity of ‘Existence’. Here, ‘Existence’ may be seen as the principle of identity as well as difference. All existents are essentially different modes of ‘Existence’. The differences among them are based on their own unique ways of existence: every concrete existent, in itself, is an individual case of ‘Existence’. Differences become real with their existential instances in the process of becoming, for example with priority and posterity, perfection and imperfection, strength and weakness resting in their existence not in their quiddity. If we rely on quiddity for bringing forth differences, then there will be no real diversity in the world, or, rather, diversity becomes an illusion because quiddity is only conceptual and is in thinking. The modes of ‘Existence’ are also different from ‘Existence’. The distinction between ‘Existence’ and its modes in the philosophy of Mulla Sadra and Heidegger is the foundation for the ‘ontological difference’ and the idea of identity in difference in the world.20 Hence, the description of ‘Existence’ as the principle of identity and of ‘quiddity’ as difference is problematic, for whatever exists in and outside the human thinking is ‘Existence’ in different modes and ‘Existence’ neither is nor has a quiddity. An assertion of the distinction between two individual instances of the modes of ‘Existence’ is not dependent on something unreal, because the difference is real. Thinking of quiddity as the birthplace of diversity renders the ‘ontological difference’ between ‘Existence’ and ‘existents’ fictitious. Total unity and identity without difference will remain outside the domain of human thinking; it will no longer be possible to talk about the gradation of ‘Existence’. We also know that the modes of ‘Existence’ that have come into being are different from ‘Existence’, and the relation between them is not like the relation between genus and species because ‘Existence’ is not a genus or a universal determination, but the reality on which every existent stands. There is no existent without ‘Existence’. At the same time an existent is not ‘Existence’ and vice versa. The ontological difference becomes a ground for a new type of relationship between ‘Existence’ and existents. On one side, it indicates their sameness or identity (not in the Aristotelian sense), and on the other it indicates their difference. This makes them identical in difference. As long as identity belongs to existence and all individual instances of the modes belong to ‘Existence’, difference is also real. It is based on the degrees of the manifestation of ‘Existence’ rather than quiddity.

The concept of ‘Existence’, like all other concepts, appears to be universal, but its universality transcends all other universal concepts. It is a unique universality and is distinct from the rest of the universal concepts. For example, the universal concept of ‘horse’ is applicable to all individual horses, and at the same time it is limited to the members of the class of ‘horse’ and does not include other kinds of animals. This universality is limited and exclusionary. By contrast, the universality of the concept of ‘Existence’ is unlimited and includes whatever exists regardless of differences. There is still another distinctive characteristic of the concept of ‘Existence’ that is not found in other universal concepts. This characteristic is revealed when ‘existence’, like a universal determination, is predicated to a subject in a proposition. It is true that, in a proposition such as (X exists), the predicate does not add anything new to the meaning of the subject (X). At the same time, the negation of this predicate will bring about a fundamental change in the reality of the subject. ‘Existence’ in this proposition is not an accidental determination like other predicables. It is the inner reality of the subject and an ontological ground for its presence in the world. Nothing is more evident and clearer than the concept of ‘existence’ in this proposition. What Sabzawari intends to explain here is that the reality of ‘Existence’ and its concept are both self-evident and do not need a definition or description.10 On the other hand, quiddity remains intellectual and has no external reality. Its distinction from existence belongs to the domain of thinking and a rationalistic apprehension of a concrete existent.

Sabzawari went further in dealing with the reality of ‘Existence’ by making a distinction between external and mental existents. For him, the mental concepts are nothing but intellectual existents: ‘A thing besides “existence” in the external world has an “existence” by itself at the mind’.21 The difference between an external existent and an intellectual existent relies on the way each one of them produces its effect.21 Real fire as an external existent is hot and burns, while the intellectual existent of fire is not capable of producing similar effects. The existence of fire is self-evident and is experienced by everyone regardless of his or her intellectual capacity; but we know that this particular existence is different from ‘Existence’. The problem arises with our knowledge of the hidden nature of this reality because it is neither accessible to reason nor can it be grasped in a definition.

The ontological difference draws a line between two realms: the realm of identity and the realm of diversity. The former is sameness and stability. It is not infected by generation and degeneration. This realm resembles the realm of ‘Being’ in Parmenides’ poem, which is described as ‘ungenerable and absolutely indestructible, unwavering, endless, ever-limb-one-whole; No was nor will: all past and future null; Since Being subsists in one ubiquitous. Now unitary and continuous’.22 It is not possible for ‘Existence’ not to be or to change into something else. In coming to be, an existent, which goes through change, should come into being out of either existence or non-existence. If it comes out of existence, it will not change because it already is. On the other hand, it cannot come out of non-existence or it would not exist because, as Parmenides believes, non-existence produces nothing and cannot become a cause for an existence. For both Sabzawari and Parmenides, there is no non-existence to stand in relation to ‘Existence’. If we think of ‘Existence’ as the sole reality and the foundation of all existents, then non-existence should not be ascribed to it. Existence has neither come to be nor will it cease to exist. At this ontological level, which is dominated by the principle of identity, ‘change’ does not take place; otherwise the identity and perfection of ‘Existence’ will be jeopardised. The denial of the reality of change is a logical consequence of the denial of ‘non-existence’ as the counterpart of ‘Existence’. Aristotle explained this point more clearly by saying that change takes place between contraries or between one contrary and an intermediate, which stands for another contrary, or between the contradictories.23 Following this belief, Aristotle denies change in ‘substance’ because it does not have a contrary. Here, there is a discrepancy between Aristotle and Sabzawari. Individual substances as particular instances of the modes of ‘Existence’ belong to the realm of identity in difference. The instances undergo change, and a process of coming to be and ceasing to be. The question that arises here is, how could an existent go through change if there is no ‘non-existence’? Sabzawari, unlike Parmenides, believes that the realm of identity in difference, which is the realm of the multiple modes of ‘Existence’ and ‘Becoming’, undergoes change due to non-existence. According to him, there are two kinds of non-existence that stand in relation to an existent. One of them annihilates its whole existence, and the other negates one, or more than one, aspect of its existence. The possibility of these two kinds of non-existence relies on the existence of the individual instances: ‘The absolute existence is a predicate used when a simple “whetherness” is in question, like “man is existent”, while the determined existence is a predicate used when a composite “whether-ness” is in question, like “man is a writer”. And the negation of these two is “absolute non-existence” and “determined non-existence”, and the negation of these two is “absolute non-existence” and “determined non-existence” respectively. The purpose of our specifying “non-existence” by the word “concept” is to indicate that this division, in the case of “existence”, is not confined to its concept, but extends to its reality’.24 When the predicate of a proposition such as ‘X is an existent’ is negated, and the whole existence of ‘x’ is annihilated, we deal with absolute non-existence of an existence known as ‘x’. The negation of one or more than one aspect of ‘x’, which is not the annihilation of ‘x’ in its entirety, will lead to determined non-existence. In the proposition ‘Socrates is not a Sicilian’, we negate one determination of Socrates, namely his being a Sicilian. The non-existence of this determination does not affect the whole being of Socrates. These two kinds of non-existence can also be called unlimited and limited. The unlimited non-existence is the total annihilation of an existent, whereas a limited non-existence is the negation of one or more than one of the determinations of an existent. Non-existence is not only logical and the property of negative propositions; it is also real because existence is real. At the same time, the reality of non-existence does not match the reality of existence because non-existence is not a ‘thing’ and a ‘thing’ is equal to an existence. Here, Sabzawari is critical of the views of some rationalist Muslim theologians, namely the Mu‘tazilas, who advocated the idea of an intermediary position between existence and non-existence for the ontological status of the divine attributes.25 This belief became part of their argument for the denial of the reality and eternity of these attributes, which were claimed by the traditionalist theologians, such as the Hanbelites. Al-Jubai (d. 933), one of the Mu‘tazila thinkers, believed that all existents were things before they came into being. Later, Abu Hashim, son of al-Jubai, developed this idea into the doctrine of Hal (state or subsistence), saying that the divine attributes were neither existents nor non-existents, but states in an intermediary position.26

The distinction between existence and non-existence lies not only in their reality, but also in the way they function causally. An existent can become a cause for another existent. Fire, for example, is a cause for burning a piece of wood. By contrast, a non-existence is a cause neither of another non-existence nor of an existence: ‘Likewise there is no real causal relationship between “non-existences”, even between two particular “non-existences”. If anyone asserts this, i.e., this causal relationship – as, for example, his assertion: the “non-existence” of a cause is the cause for the “non-existence” of the caused – the assertion is based on approximation and is but a figurative expression. For asserting their being causes is due to their resemblance to their positive counterparts’.27 Furthermore, Sabzawari insists that the distinction between the non-existences is a fiction or only in the imagination.27 The denial of the causal relationship between non-existences, or between non-existence and an existence, can be problematic and requires further attention. Sabzawari has explained this in an example of the causal relationship between clouds and rain. It is usually thought that the existence of the clouds in the sky would become a cause for rain. This determines the causal relationship between two existents, namely, the clouds and the rain. When there are no clouds in the sky we change our affirmative proposition into a negative one, and assert that the non-existence of clouds in the sky is the cause for the non-existence of rain or for the existence of a sunny day. Similarly, we assume that the non-existence of fire is a cause for the non-existence of heat in the room. This is based, according to Sabzawari, on the conversion of an affirmative proposition into a negative one and has nothing to do with reality.

Here, we may think of non-existence as having no ontological significance because it is not a thing and cannot become a cause for anything in the world: but how could an unreal non-existence in its absolute and determined forms become a vehicle for change in the realm of ‘Becoming’? How can we deny the distinction between them? The non-existence of Socrates is the negation of his existence; at the same time this non-existence is real because Socrates is no longer an existent. Besides, non-existence, like existence, can become a cause and produce its own effect. Otherwise, there would be no coming to be and ceasing to be. If non-existence is not a cause for an effect and produces nothing, then we stand with Parmenides and reject the reality of change. Sabzawari accepts Parmenides’ paradigm at the ontological level of ‘Existence’, but he believes in the reality of change in the realm of ‘Becoming’. The non-existence of clouds is, therefore, not a mere conceptual expression and a property of a negative proposition. It is an existentialist reality of the non-existence of clouds, which becomes a cause for the non-existence of rain and the existence of a sunny day. This does not mean that whenever there are clouds there would be rain, but that there is no rain without clouds. In the same manner, the non-existence of oxygen in a room will be fatal. This non-existence cannot be seen as something unreal or only in the imagination because its effect is real.

After describing two kinds of non-existence, namely, absolute and determined, Sabzawari accepts no distinction between the non-existences as far as they are non-existences. According to him, one cannot determine the difference between the non-existence of Socrates and that of a chair, or the non-existence of Socrates and the non-existence of being Sicilian. But can a distinction be made between two existences? As explained earlier, Sabzawari believes that existence is univocal and homogeneous. It is shared by all existents. This will make the existence of Socrates and that of a chair identical and the same. The differences and diversity arise, as Sabzawari reckons, when their universal determinations or quiddities are analysed. There is no real distinction between them as far as existence is concerned. Their distinction is in their quiddity, which is conceptual and corresponds to nothing outside human thinking: ‘The “quiddities” by themselves are different from each other, and multiple, and spread the dust of multiplicity throughout “existence”, for “existence” becomes multiple in a certain way through the multiplication of its subjects, just as “existence” is the very centre about which turns the sphere of unity’.19

Sabzawari also advocates the idea that non-existence came to the world with human intellect. This idea is interesting and reminiscent of Jean-Paul Sartre’s analysis of nothingness in his major philosophical work Being and Nothingness (1943), where he describes nothingness as an aspect of consciousness, which is born with it and can also be experienced.28 In the same manner, Sabzawari states, ‘Our intellect has the power to represent the “non-existence” of itself. Thus the intellect is necessarily qualified by “existence” and “non-existence”. And also it has the power of representing the “non-existence” of others, namely other external “existents” so that the latter must likewise be qualified by “existence” and “non-existence”’.29 The human intellect, unlike other kinds of existents such as a table, is aware of its own deficiency. This awareness refers to the non-existence of some aspects of this being. The human intellect is born with this deficiency, and endeavours constantly to accomplish itself. Sartre also holds the view that nothingness is made to be and ‘appears within the limits of a human expectation’.30 In this way the non-existence of a table in the room is a factor experienced by the human intellect. I experience this non-existence in the world. Without my presence there will be no non-existence. I also understand my own existence as lacking, or, as Sartre says, ‘I am not what I am and I am what I am not’.31

It should be remembered that the apprehension of non-existence by the human intellect does not make non-existence subjective or only conceptual. Sabzawari’s claim is also true for existence, which, like non-existence, is revealed to the human intellect. The existence as well as the non-existence of a table is revealed to my consciousness equally, but that does not mean that they cannot be without my existence in the room. This is not solipsism; the presence of the human intellect is a condition for the revelation of both existence and non-existence. It is I myself not a non-conscious entity like the chair that experiences the existence and non-existence of the table in the room. Moreover, since the division of non-existence is made on the division of existence and non-existence is understood in relation to existence, non-existence should be prior or posterior to existence. In the case of something coming into being, non-existence precedes existence and becomes prior to it, whereas in ceasing to be, non-existence becomes posterior to existence. In both cases, in coming into existence and ceasing to be, non-existence has an ontological significance and impact on existence and its dynamic character. In addition to this, we conclude that ‘existence’, which is seen as the principle of unity, will also become the ground for diversity in the realm of ‘Becoming’.

For Suhrawardi’s arguments against the principality of Existence see: Shahab al-Din Suhrawardi, Hikmat al-Ishraq (The Philosophy of Illumination), translated by John Walbridge and Hossein Ziai, Provo, Utah: Brigham Young University Press, 1999, pp. 44–46.

Seyyed Hossein Nasr, Sadr al-Din Shirazi and his Transcendent Theosophy, Tehran: Institute for Humanities and Cultural Studies, 1997, p. 69.

Mulla Sadra, al-Asfar al-Arba'a, vol.1, Beirut: Dar Ihya' al-Turath al-'Arabi, 1999, pp. 68–69.

Mulla Sadra, al-Asfar, vol. 1, p. 432.

Mulla Ali Jamshid Nuri (d. 1830) was a great scholar and profound Sadrian philosopher who studied at Mazandaran and Qazvin, and settled in Isfahan. He taught the philosophy of Mulla Sadra and the mystic ideas of Shaykh Ahmad Ahsa‘i, the founder of the Shaykhi Sufi order. He was also the teacher of Mulla Ismail Isfahani, Mulla Abdullah Zunuzi, Mulla Agha Qazvini, Muhammad Rida Qumshahi and Mulla Hadi Sabzawari. The Qajar ruler, Fath Ali Qajar, founded Khan Marvi’s school and invited Mulla Ali Nuri, a profound Sadrian scholar and philosopher, to teach philosophy in Tehran. It seems that Mulla Ali Nuri did not accept the offer but sent Mulla Abdullah Zunuzi, one of his students, to undertake this responsibility while he himself stayed in Isfahan. Mulla Hadi Sabzawari also studied philosophy with Mulla Ali Nuri for ten years.

Henry Corbin, History of Islamic Philosophy, London and New York, in association with Islamic Publications for the Institute of Islamic Studies, 1993, p. 351. See also: Seyyed Hossein Nasr, ‘The Metaphysics of Sadr al-Din Shirazi and Islamic Philosophy in Qajar Iran’, in Qajar Iran: Political, Social and Cultural Change 1800–1925, (eds.) Edmund Bosworth and Carole Hillenbrand, Edinburgh: Edinburgh University Press, 1983, pp. 190–91.

Mulla Sadra, al-Masha‘ir, translated by Parviz Morewedge, New York: SSIP, 1992, section 57, p. 30.

Shahab al-Din Suhravardi (1171–1208), another Muslim philosopher, who advocated the principality of essence and is known as the founder of Illuminationism, believed in the illuminative presence of knowledge by presence.

Mulla Hadi Sabzawari, The Metaphysics of Sabzawari, translated from the Arabic by Mehdi Mohaghegh and Toshihiko Izutsu, New York: Caravan Books, 1977, p. 33. This book is commonly known as Sharh-i manzumah (Commentary on a Philosophical Poem). The commentary, entitled Ghurar al-fara’id, is divided into seven headings. Each heading deals with one aspect of Sabzawari’s philosophy. They are further divided into chapters and sections.

Mulla Hadi Sabzawari, The Metaphysics of Sabzawari, p. 31.

Mulla Sadra, al-Masha‘ir, pp. 7–8.

Martin Heidegger, Being and Time, translated by John Macquarie and Edward Robinson, London: Blackwell, 1992, p. 23. I have discussed the problem of the definition of ‘Existence’ in the philosophy of Mulla Sadra and Martin Heidegger in my book From Essence to Being: The Philosophy of Mulla Sadra and Martin Heidegger, London: ICAS Press, 2010, pp. 101–6.

These predicables are relations between a universal term and a subject in a proposition. Aristotle mentioned four of them: genus, specific difference, property and contingent accident. Later, Porphyry (234–c. 305 AD) added Species as the fifth predicable.

Mulla Hadi Sabzawari, The Metaphysics of Sabzawari, p. 32.

Mulla Hadi Sabzawari, The Metaphysics of Sabzawari, p. 35.

Toshihiko Izutsu, The Fundamental Structure of Sabzawari’s Metaphysics, Tokyo: Keio University Press, 1971, p. 51.

Mulla Hadi Sabzawari, The Metaphysics of Sabzawari, p.43.

Mulla Hadi Sabzawari, The Metaphysics of Sabzawari, p. 44.

Mulla Hadi Sabzawari, The Metaphysics of Sabzawari, p. 37.

Mulla Sadra, Al-Asfar al-Arba‘a, vol. 1, introduction by Shaykh Muhammad Rida al-Muzafar, Beirut: Dar al-Ahya’ al-Turath al-‘Arabi, 1999, p. 59. Martin Heidegger defined the ontological difference as the differentiation between Being and beings in The Basic Problems of Phenomenology, translated by Albert Hofstadter, printed by Indiana University Press in 1982 (see pages 17, 72 and 78).

Mulla Hadi Sabzawari, The Metaphysics of Sabzawari, p. 54.

Martin, J. Henn, Parmenides of Elea, a verse translation with interpretative essays and commentary to the text, London: Praeger, 2003, p. 26.

Aristotle, ‘Metaphysics’, Book Kappa, 12: 10–20, and ‘Categories’, 3b 24–32, in The Complete Works of Aristotle. Aristotle also explained his ideas on change and movement in ‘Physics’ Book 5, 1 and 2.

Mulla Hadi Sabzawari, The Metaphysics of Sabzawari, pp. 69–70.

Mulla Hadi Sabzawari, The Metaphysics of Sabzawari, pp. 75–77. These rationalist Muslim theologians were the members of the Mu‘tazila school founded in Basrah and Baghdad by some pupils of Hasan al-Basri (642–728) who had seceded from him. The Mu‘tazila attempted to interpret religion in the light of human reason. They strongly advocated the Unity of God (al-tawhid) by denying the reality and eternity of the Divine attributes, and believed in Divine Justice. For that they were called the people of Justice and Unity of God (Ahl al-‘Adl wa al-Tawhid). They also advocated the doctrine of free will.

Al-Shahrastani, Nihayat, Cairo, 1960. P. 132.

Mulla Hadi Sabzawari, The Metaphysics of Sabzawari, p. 79.

Jean-Paul Sartre, Being and Nothingness: An Essay on Phenomenological Ontology, translated by Hazel E. Barnes, Routledge: London, reprinted 1996, p. 7.

Mulla Hadi Sabzawari, The Metaphysics of Sabzawari, p. 84.

Jean-Paul Sartre, Being and Nothingness, p. 7. (Sartre also believes that nothingness provides the ground for negation and negative propositions and not vice versa (see p. 19).

Jean-Paul Sartre, Being and Nothingness, p. 79.

Copyright information

© Springer Science+Business Media B.V. 2011


Giving customers a glimpse into a food truck owner’s life and mindset can allow them to cultivate a deeper relationship with customers separately from the brand. The goal, of course, is to increase customers’ loyalty to the brand.

Here are a few things every food truck owner (new or old) can tweet about, which can allow your customers to see another side of you:

Personal News

Share the big events of your personal life (vacations, weddings, births) you, the type of information you’d share with close friends. It can help keep your followers feeling like they’re “in the loop.” You’re also more likely to make a connection with followers who have experienced something similar.

They key to sharing articles is to also include your unique opinion. Let others know why you liked or didn’t like the specific article. Just remember that your opinion paints a public image, which means you should be cautious about which opinions you choose to share.

Wisdom from the book you’re reading

Sharing your recent purchases, such as music or home cooking equipment can stir up comments and conversations from others that have bought similar items and enjoy the same types of things.

Share Wisdom

The greatest information you can share is from the work you do in your life, but don’t limit that to what you do in your food truck only. If you have a hobby or passion for something creative outside of the food you serve, share it.

[poll id=”39″]

So what types of tweets would you add to this list? Feel free to let us know in the comment section below.