Brethren of the Free Spirit
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The Brothers, or Brethren of the Free Spirit, was a lay Christian movement which flourished in northern Europe in the 13th and 14th centuries. Antinomian and individualist in outlook, it came into conflict with the Catholic Church and was declared heretical by Pope Clement V at the Council of Vienne (1311–12). They are often considered similar to the Amalricans. They flourished at a time of great trauma in Western Europe during the conflict between the Avignon Papacy and the Holy Roman Emperor, the Hundred Years' War, the Black Death, the rise of the Cathar heresy and the subsequent Crusade against them, the beginnings of the Inquisition, the fall of the Templars and the internal strife of the Church — all of which helped fuel the appeal of their individualistic and millenarian approach to Christianity and Scripture.
In this time of crisis within the Church and society as a whole there was a strong sense that the end of the world was coming and so the issue of Man's spirituality and salvation became more and more important. Where people ceased to find the spiritual answers they sought from Rome, dissident movements like the Brethren sprang up all across Europe preaching an alternative view of Christianity. They fell foul of the Church and were persecuted as heretics by the temporal and spiritual authorities of the time.
From the very beginning of what would become the Free Spirit Heresy its followers ran into trouble with the secular and religious authorities. Both Amaury de Bene and Giochinno de Fiori, whose ideas could be said to be at the fountainhead of the movement, underwent examination and persecution at the hands of the Church. Amaury's writings were condemned in 1204, Amaury himself dying in 1207 having been forced to recant his views. In 1209 ten of his followers were burnt at the stake in Paris, and Amaury's body was exhumed, also burnt and the ashes scattered. By 1215 his work and followers were formally condemned by the Fourth Lateran Council and denounced as officially heretical.
In spite of the support of earlier Popes and his popularity among the people, in 1200 Gioacchino da Fiore submitted his works to Pope Innocent III for examination but, like Eckhart after him, died before judgement could be carried out. Some of his ideas were officially condemned along with Amaury's at the same Lateran Council of 1215 and his followers, the Joachimites, were brutally suppressed by the Church against whom they were starting to preach. By this time, with the rise of the Cathar movement in the south of France, the Church was increasingly on its guard against the threat of heresy.
Nevertheless the spread of Free Spirit ideas continued along with other possibly related Christian lay movements such as the Beguines and Beghards, even after the suppression of other heresies such as the Cathars and the Waldensians. By the 14th century the movement had spread widely across the Champagne, Thüringen and Bavaria and more northwards into what is now Belgium and Holland. It was during this time that works such as Porete's The Mirror of Simple Souls and Mechtild of Magdeburg's Light Flowing from the Godhead were being written and Meister Eckhart was preaching. As the heresy spread the Inquisition moved in to combat and root it out. Porete was burnt at the stake in 1310, Eckhart was put on trial in 1327 and other important Christian mystics, such as Jordan von Quedlinburg, Henry Suso and John of Ruysbroek spoke out against the heresy — even though some (Ruysbroek in particular) expressed similar ideas such as the immanence of God and the possibility of union with Christ in this life. Where they differed with the Brethren was in their belief in the validity of the Church and the need to experience these things within its framework. Eckhart himself denied that he had anything to do with the Free Spirits and insisted that his thinking remained within orthodox boundaries. Nevertheless he was forced to recant various ideas he had propounded that seemed to overlap them before he disappeared from public life.
From 1300 to 1350 the Brethren were found largely on the Rhine from Cologne to Strasbourg. In Brussels a similar movement appeared known as the Homines Intelligentiae or Men of Understanding. Towards the end of the 14th century the Lollards in England emerged, sharing many doctrines with the Free Spirit, as well as those of the Cathars and Waldensians. As with all these movements, the common ground included rejection of the Church as corrupt, a belief in the presence of God in the human soul via the Holy Spirit and the need to work out a grassroots salvation of mankind individually. The growing lay Christian movement with ecclesiastical connections, the secretive Friends of God, who are thought by some to have provided protection and anonymity for Meister Eckhart after his trial, may have absorbed some of the Brethren and their ideas into their ranks during the escalation of Church persecution of heretical movements. Johannes Tauler and Henry Suso are associated with this movement, although their view of the Brethren is disputed, Suso in particular preaching against them. The influential "anonymous" treatise, Theologia Germanica, was dissiminated during this time amongst many "heretical" groups and its approach to Brethren-like purification — mirroring Eckhart's style and language usage — became very influential. Some historians give it credit for the ultimate actions taken by Martin Luther, who prized the document, and the subsequent Protestant Reformation a century and a half later, although doctrinally Luther and the Reformation were very different from the Free Spirits.
Many edicts were published against the Brethren. In 1312 the Council of Vienne finally putting paid to any possibility of their avoiding the charge of heresy. But, notwithstanding the severities which they suffered, records show that the followers of the Free Spirit heresy continued until about the middle of the fifteenth century. Some sources identify their beliefs as precursors of later Christian movements such as the Ranters and the Quakers. Similarly, ideas reminiscent of the Free Spirit heresy can be found in the works of the poet and artist William Blake who preached a similar revolutionary, Gnostic Christianity (e.g. "One law for the lion and the ox is oppression... for everything that lives is holy" The Marriage of Heaven and Hell).
Relationship to other Christian lay movements 
There is considerable confusion as to the relationship between the Brethren and other lay Christian movements of the time: the Beguines and Beghards with whom they were often confused. Indeed some have argued that the Brethren didn’t exist at all in the commonly held idea of a movement. It had no central leader, hierarchy or organisation and was very difficult to define. Such a view holds that rather than speaking of a Brethren of the Free Spirit in the same way as we speak of the Cathars, the Lollards or the Waldensians, we should talk about a Doctrine or Heresy of the Free Spirit or even little more than a loose set of ideas grouped together under a single title, i.e. "a state of mind as much as a settled body of doctrine", as British scholar Gordon Leff states it.
Not everyone accused of being a member of the Free Spirit or of disseminating their doctrines was part of the movement. Even at the Council of Vienne the Church authorities struggled to bring together documentation of what the Free Spirit stood for, using texts such as Marguerite Porete's The Mirror of Simple Souls as evidence of what the Brethren said. The very fact that no one spiritual thinker can be identified as the movement's founder (names linked to the movement include Amaury de Bene, Giochinno de Fiori and Meister Eckhart, all of whom, at different times, were cited by individuals proclaiming their adherence to the Heresy as the originators of their beliefs), or claimed to be so, indicate how disparate a movement it was.
As mentioned above, defining the doctrine of the Brethren of the Free Spirit is a complex undertaking. Central to their belief seem to be three fundamental ideas:
1. That God is incarnate/immanent in everything.
- Sometimes described as a form of pantheism, the idea is similar to the neo-Platonic view that God is both immanent and transcendent. For the Brethren this meant that God was present in creation and in humanity. Both Marguerite Porete and Johannes "Meister" Eckhart, who were tried as heretics and accused of preaching Free Spirit doctrines, cite the words of St Paul in the New Testament to argue:
- "All things are from Him, through Him and in Him." (Romans 11:36)
- Porete expressed the same concept thus:
- "Beloved, what do you wish from Me? I contain all things which were, and are, and shall be, I am filled by all things. Take from me all which pleases you: If you desire from me all things, I will not deny. Say, Beloved, what do you wish from me? I am Love, filled with the goodness of all things: What you will, we will. Beloved, tell us plainly your will." (The Mirror of Simple Souls trans: Ellen Babinsky 1993)
- Amaury de Bene is often identified as being the originator of this concept, but it had been present as a doctrine in the Church since its inception in the works of Christians influenced by Platonism such as Pseudo-Dionysius, Pelagius and John Scotus Eriugena, especially in its Eastern (Byzantine) incarnation.
- At the time of the Free Spirit movement it was viewed as heretical by the Western Church, which argued that God was exclusively transcendent and not present in Creation at all. Through this belief the Brethren rejected the Catholic idea of Transubstantiation (only recently doctrinally defined at the time), believing instead in Consubstantiation at most and a complete rejection of the idea of the need for the Eucharist at all in other cases.
2. That history was divided into three periods, each corresponding to a different aspect of the Trinity.
- The first, the Age of the Father, corresponded with the era of the Old Testament (Abraham, Moses and the Prophets etc). The second, the Age of the Son, corresponded to the coming and ministry of Christ and the first millennium or so of Christianity. The last and final era was the Age of the Holy Spirit or the Paraclete as it is described in the New Testament, when God would become manifest in Man. Giochinno de Fiori was the first to develop this doctrine, basing his ideas on a close reading of Revelation ("Grace be unto you, and peace from Him which is [the Son],and which was [the Father] and which is to come [the Holy Spirit]" Revelation 1:4). The Brethren of the Free Spirit believed that this era was coming to pass and, with the incarnation of God in all humanity, the Last Days before the dawn of the 'New Heaven and New Earth'.
3. That through a direct experience of God in which the Holy Spirit flourishes in the individual soul Man could achieve a union with God which meant that he could no longer sin.
- Of all the three central ideas of the Free Spirit movement this was the most difficult to understand, the most shocking to the Church and the most open to abuse. This concept of a mystical union with God in this lifetime — the opposite of the Catholic doctrine of the Beatific Vision after death (that Man could only 'see Him as He is' after death) - was seen as being a form of Resurrection or eternal aliveness in this world, the Soul having died and been reborn in God while still incarnate (an interpretation of the Resurrection found also in some of the early Gnostic movements).
- Individuals who had achieved this state of being were called 'the Spiritualised', having received the 'indwelling' of the Holy Spirit through uniting with love as described in the book of Acts. (The term 'indwelling' is also used in the Kabbalah as a translation of Shekhinah, or the Glory of God, which is seen to dwell within the human soul.) Such individuals saw themselves as having evolved beyond ordinary states of good and evil (duality), replacing notions of faith and hope (beliefs in things which might be) with the positive light of knowledge (Gnosis, or direct knowledge of God).
- Although they did not use the terminology of the Gnostics, nor did they probably even know of them, their use of the words 'knowledge' and 'ignorance' as different states of spiritual awareness are strikingly reminiscent of the earlier movement as they are of the terminology of other religions and mystical movements such as Buddhism and Sufism. This experience of Oneness with God and the difficulty of expressing it often lead to hostile listeners accusing members of the Free Spirit of blasphemy. Thus expressions such as:
- "Father rejoice with me, I have become God... When I looked into myself I saw God within me and everything he has ever created in heaven and earth... I am established in the pure Godhead, in which there never was form or image." (Sister Catherine Treatise, trans: Elvira Borgstaedt 1986)
- were met with horror and anger by the Church who saw the normal relationship of Man to God being usurped and turned on its head. Achieving this union with God happened through an austere process of self-abnegation and annihilation of the Ego, according to mystics such as Eckhart and Porete. What disturbed the authorities was what the followers of the Free Spirit felt they could do afterwards, once they had attained this supposedly sinless state and their assertion that the mediation of the Church was irrelevant.
- These fundamental elements of the movement meant that they rejected the validity or even the need for the Church in favor of an individual approach to God. Like the Cathars, they therefore rejected the sacraments as well. Some saw the Church as the active enemy of God, describing the Church as the Anti-Christ, again something they had in common with the earlier sect. They also rejected the secular authorities, citing Christ's injunction forbidding oaths and preached an egalitarian approach to Christianity which did not recognise distinctions of gender. Some have seen them as proto-anarchists in their refusal to acknowledge hierarchies of any kind. Whatever the case, few of their views could be expected to endear themselves either to the Church or the feudal authorities who ruled the regions in which they flourished.
Scriptural justification 
Although not orthodox in interpretation, many of the ideas of the Free Spirit can be seen echoed in the Bible. In their preaching and literature followers of the Free Spirit (or rather those accused of being so) often drew justification, inspiration and imagery from Scriptural sources.
For instance, ideas of the 'indwelling' in Man of the Holy Spirit, the possibility of a union between Man and God in this life, an egalitarian relationship to God among humanity and the impossibility of sin once a union with God through Love has been established can be (and was) extrapolated from the following extracts:
- "Beloved, now we are the Sons of God, and it doth not appear what we shall be: but we know that, when He shall appear, we shall be like Him; for we shall see Him as He is. And every man that hath hope in Him purifieth himself, even as He is pure. Whosoever commiteth sin transgresseth also the law: for sin is the transgression of the Law. And ye know that He was manifested to take away our sins: and in Him is no sin. Whoesoever abideth in Him sinneth not: whoesoever sinneth hath not seen Him, neither known Him" (First Epistle of John 3:2–6)
- "Neither pray I for these alone, but for them also which shall believe in me through their word; that they all may be one; as thou, my Father, art in me, and I in thee, that they also may be in us: that the world may believe that thou hast sent me. And the glory which thou gavest me I have given them; that they may be one, even as we are one. I in them, and thou in me, that they may be made perfect in one; and that the world may know that thou hast sent me, and hast loved them, as thou hast loved me" (Gospel of St John 17:20–23)
- "And it shall come to pass in the last days, saith God, I will pour out my spirit upon all flesh: and your sons and daughters shall prophesy, and your young men shall see visions, and your old men shall dream dreams: And on their handmaidens I will pour out in those days of my Spirit; and they shall prophesy: And I will shew wonders in the heaven above..." (Acts 2:17–21)
The egalitarian vision of the Free Spirit which recognised no barriers of race, class or gender before God can be interpreted from the words of St Paul:
- "There is neither Jew nor Greek, there is neither bond nor free, there is neither male nor female: for ye are all one in Jesus Christ. And if ye be Christ's, then are ye Abraham's seed, and heirs according to the promise." (Galatians 3:28–29)
Similarly the idea of the journey towards union with God as an inner one can be interpreted from this passage in the Gospel of Luke:
- "And when he was demanded of the Pharisees, when the kingdom of God should come, he answered them and said, The Kingdom of God cometh not with observation: Neither shall they say, Lo, here! or, lo there! for, behold, the kingdom of God is within you." (Gospel of Luke 17:20–21)
Perhaps the clearest use of the Bible in a text associated with the Free Spirit is that found in Marguerite Porete's The Mirror of Simple Souls. Compare, for example, this passage from John's Epistle:
- "Beloved, let us love one another, for love cometh of God. And every one that loveth, is born of God, and knoweth God. He that loveth not, knoweth not God; for God is love... If we love one another, God dwelleth in us, and His love is made perfect in us. Hereby know we that we dwell in Him, and He in us, because He hath given of his spirit... Whoesoever confesseth that Jesus is the son of God, in Him dwelleth God, and he in God... For God is love, and He that dwelleth in love dwelleth in God, and God in him... For as He is, even so are we in this world" (First Epistle of John 3)
With Porete's words in her work:
- "I am God, says Love, for Love is God and God is Love, and this Soul is God by righteousness of Love. Thus this precious beloved of mine is taught and guided by me, without herself, for she is transformed into me, and such a perfect one, says Love, takes my nourishment" (The Mirror Of Simple Souls. Trans: Ellen Babinsky 1993)
All these strands of thought, coupled with a visionary, millenarian view of universal Christian redemption are perhaps found in the words of Paul in Athens in Acts:
- "God that made the world and all things therein, seeing that He is Lord of Heaven and Earth, dwelleth not in temples made with hands; neither is worshipped with men's hands, as though He needeth anything, seeing He giveth to all life, and breath, and all things; and hath made of one blood all nations of men for to dwell on all the face of the earth, and hath determined the times before appointed, and the bounds of their habitation; that they should seek the Lord, if haply they might feel after Him, and find Him, though He be not far from any of us; for in Him we live, and move and have our being; as certain of your poets have said, for we are also His offspring" (Acts 17:24–28)
A peculiarity of some of the writings and doctrines of the Free Spirit movement is in their echoes of Gnostic ideas in texts such as the Gospel of Thomas and the Gospel of Philip. Imagery of the need to be 'naked' or purified before encountering salvation, the possibility of the Resurrection being a spiritual state of fullness experienced in this life rather than the next, the importance of Mary Magdalene, and descriptions of becoming drunk on the Holy Spirit all can be found in Thomas and other Gnostic writings as well as in the practises of various Free Spirit gatherings (some Beghard congregations are said to have conducted Masses nude), the Sister Catherine Treatise and the work of Marguerite Porete. A typical parallel, for instance, can be seen in the following extract from Thomas, which seems to endorse the pantheism of the Free Spirit's followers:
- "It is I who am the light which is above them all. It is I who am the all. From me did the all come forth, and unto me did the all extend. Split the piece of wood, and I am there. Lift up the stone, and you will find me there." (Gospel of Thomas)
Similarly, the idea that one who has Knowledge (Gnosis) or Union with God cannot and does not sin is found in Philip:
- "The one who has Knowledge is a free person. But the free person does not sin, for the one who sins is a slave of sin." (Gospel of Philip 77:15–18)
Whether these echoes are circumstantial or not is up for debate, especially as these Gospels were presumed lost until their discovery among the Nag Hammadi manuscripts in the 20th Century. It is possible that such Gnostic ideas or texts were in circulation in the areas where the Free Spirit flourished via the Cathars, whose dualistic and transcendentalist approach to Christianity had its roots in the East but this is unproven, although it is true that the regions where the Cathars were strongest in northern Europe — Flanders, the Rhineland, Cologne — were the regions where the Free Spirit spread most strongly. Whatever the case the parallels are there and very striking.
Expression of the Free Spirit 
For all the reasons given above it is hard to establish who was representative of the Free Spirit and who was not. Similarly, perceptions of how members of the movement behaved are complex and multifarious. Although sharing similar ideas about how to interpret the Bible — antinomian, egalitarian, believing in a mystical apprehension and union with God in this life — how this happened in practice is hard to determine. For instance, there is no evidence in Porete's work that amorality was justified. Although Porete argues that the Unencumbered or Annihilated Soul is above the Virtues and demands of Holy Church she believes that sin is not possible, because the Soul is now One with God, sin is simply not available to it as an option:
- "This Soul has given everything through the freeness of the nobility by the work of the Trinity, in which Trinity this Soul plants her will so nakedly that she cannot sin if she does not uproot herself. She has nothing to sin with, for without a will no one can sin. Now she is kept from sin if she leaves her will there where she is planted, that is, in the One who has given it to her freely from His goodness. And thus, by His beneficence, He wills the return of His beloved nakedly and freely, without a why for her sake, on account of two things: because He wills it, and because He is worthy of it. And before this she had no fertile and restful peace until she was purely stripped of her will." (The Mirror Of Simple Souls. Trans: Ellen Babinsky 1993)
Porete's expression of Free Spirit ideas is highly mystical and predicates the idea of the impossibility of sin on this mystical union with God through Love. This view of the ideas of the Free Spirit suggests that among certain of its members a complete giving over of the individual to a spiritual relationship with God is the goal of the believer. It is echoed in other works and sayings of people accused or suspected of expressing Free Spirit heresies such as Meister Eckhart and the unknown author of the Sister Catherine Treatise. Nowhere in these writings is a belief in unbridled sensuality countenanced, in fact exactly the opposite, the woman speaker in the Sister Catherine Treatise, for instance, expressing her desire never to "diverge from the path of our Lord Jesus Christ" after her personal union with God. Scholar of the movement Ellen Babinsky summarizes this view thus:
- "The Free Spirits were committed to poverty and mendicancy as an outgrowth of the vita apostolica movement. The centrepiece of the Free Spirit perspective seems to be that an arduous ascetic practice was necessary to attain the divine life of union with God. In this view, only through extreme purgation could one divest the self of all will and desire in order to achieve perfection. The motivation for the Free Spirit was the search for spiritual perfection, not a revolutionary antipathy to the Church, as some scholars have thought" (The Mirror Of Simple Souls. Introduction: Ellen Babinsky 1993)
On the other hand there are copious records of the use of the Free Spirit interpretation of Scripture to justify non-monogamous sex, violence, robbery and rape. Whether these records are merely anti-heretical propaganda (other heretical movements such as the Cathars were accused of similar crimes) or not is unclear. The sheer volume of evidence suggests that there was abuse of the ideology, particularly by those who professed to follow the heresy who were not living in closed communities such as Beguine and Beghard settlements. The image presented is of roving bands or isolated individuals traveling across Europe spreading havoc with their amoral, millenarian vision of Christianity. Free Spirit heretics were accused of enjoying group sex, of conducting masses naked, claiming that they were God and, in one instance, that there was no God and that blind chance ruled the universe. Historian Barbara Tuchman vividly conjures up this vision of moral and religious anarchy in her seminal book on the Middle Ages, A Distant Mirror, :
- "The Brethren of the Free Spirit, who claimed to be in a state of grace without benefit of priest or sacrament, spread not only doctrinal but civil disorder....Because the Free Spirit believed God to be in themselves, not in the Church, and considered themselves in a state of perfection without sin, they felt free to do all things commonly prohibited to ordinary man. Sex and property headed the list. They practiced free love and adultery and were accused of indulging in group sex in their communal residences. They encouraged nudity to demonstrate absence of sin and shame. As 'holy beggars', the Brethren claimed the right to use and take whatever they pleased, whether a market woman's chickens or a meal in a tavern without paying. This included the right, because of God's immanence, to kill anyone who forcibly attempted to interfere" (A Distant Mirror: the Calamitous Fourteenth Century 1979)
Here we find the central paradox in evaluating the Free Spirit. Both extracts speak of the same root belief — that the soul in union with God cannot sin. Where one suggests that to achieve this state is arduous and involves a process of purification, the other sees that once the state of union with God exists, by any means, easy or hard, it justifies what would be seen as immoral acts in the authoritarian churches of that time (or this). The Free Spirit heresy challenged the authority of the Church, which traditionally used accusations of sexual perversion and immorality to attack heretical movements. Individuals who lived exemplary lives were also suspected of Free Spirit leanings (such as Meister Eckhart and even John of Ruysbroek who preached against the movement). The Free Spirit interpretation of the Bible, like any doctrine, was open to interpretation, with some following a more conventional path for the time, and others using the doctrines to provide themselves with a more freedom than was commonly available under Church rule.
This ambiguity inherent within the movement is perhaps well illustrated in the following extract from a Beghard writer who was clearly influenced by the ideas of the Free Spirit:
- "Moreover, the godlike man operates and begets the same that God operates and begets. For in God he worked and created heaven and earth. He is also the generator of the eternal word. Nor can God do anything without this man. The god-like man should, therefore, make his will conformable to God's will, so that he should will all that God wills. If, therefore, God wills that I should sin, I ought by no means to will that I may not have sinned. This is true contrition. And if a man have committed a thousand mortal sins, and the man is well regulated and united to God, he ought not to wish that he had not done those sins; and he ought to prefer suffering a thousand deaths rather than to have omitted one of those mortal sins." (quoted from Mosheim, Institutes of Ecclesiastical History, II. v, 11)
The similarities but also the differences with the words of Porete are clear, as is the difficulty of understanding quite what the morality of the extract is, and how easily it could be misconstrued.
This interpretation of the role of sin on the road to an understanding of God is not dissimilar to that put forward by English mystic Julian of Norwich in her work Revelations of Divine Love, in which she says that, although undesirable, 'sin is behovely' as through repentance sin can become part of God's pattern whereby the soul can reach God. Again, Julian, like Porete, is at pains to explain that this is not to justify sin (both argue that sin is something to be avoided) but to understand its place in the universe — that sometimes before one reaches a state of bliss in union with God one cannot avoid sinning but that when it is rightly understood, those sins are forgiven, thus becoming part of God's plan in guiding the Soul to God. It is significant that Julian was not branded a heretic while Porete and other supposed followers of the Free Spirit were. Where Julian differed from Porete perhaps, was in her belief that the union with God and the particular view of the role of sin she spoke were possible within the established structure of the Church and not in opposition to it.
In fiction 
The Brethren of the Free Spirit are the main antagonists of the science fiction trilogy Venus Prime by Arthur C. Clarke & Paul Preuss, in which the members believe that first contact between aliens from Crux and humanity should be with them only. The cult suborns a school project at The New School For Social Research, SPARTA, and then takes its principal student, Linda Nagy, as the herald of the cult, setting in motion the main events of the trilogy.
See also 
- Acts - Gospel of John - First Epistle of John - Revelation
- Amaury de Bene
- Beguines and Beghards
- Christianity - Christian mysticism - Esoteric Christianity
- Council of Vienne
- Giochinno de Fiori
- Gnosticism - Gospel of Philip - Gospel of Thomas
- Heresy of the Free Spirit
- List of Christian mystics
- Marguerite Porete - The Mirror Of Simple Souls
- Meister Eckhart - Sister Catherine Treatise
- Rosicrucianism - Rosicrucian Manifestos
- Theologia Germanica
- Norman Cohn, The Pursuit of the Millennium, Secker and Warburg, London, 1957
- Robert Lerner, The Heresy of the Free Spirit in the Later Middle Ages, Berkeley, 1972
- Marguerite Porete, The Mirror of Simple Souls, ed. Ellen Babinsky. Paulist Press, 1993. ISBN 0-8091-3427-6
- Barbara Tuchman, A Distant Mirror, Alfred A Knopf Inc, New York, 1978. ISBN 0-333-64470-0
- Raoul Vaneigem, The Movement of the Free Spirit, Zone Books, 1994
- Walter Wakefield and Austin Evans, Heresies of the High Middle Ages, Columbia University Press, New York, 1991
- Catholic Encyclopaedia 
- Christopher McIntosh: The Rosicrucians: The History, Mythology and Rituals of an Esoteric Order Weiser Books 1988
- John Ruusbroec (John of Ruysbroek): The Spiritual Espousals and Other Works. Introduction and translation by James A Wiseman, OSB. Preface by Louis Dupre. Paulist Press 1985. ISBN 978-0-8091-2729-0
- History of the Christian Church: Heresy and its suppression
- Blessed Henry Suso Wrote Büchlein der Wahrheit (Little Book of the Truth), "written in part against the pantheistic teachings of the Beghards, and against the libertine teachings of the Brethren of the Free Spirit."