It is not the diet, as assumed by Readership of Cornaro's illustration, that is the cause of good health, but rather an underlying condition that caused or, otherwise, gave rise to the success of this diet, and hence the longevity of this man. The parallel to morality runs the usual aretic formula to the ground, whereby tis not the virtues that are understood to lead (cause) to the good life, but rather a degenerate state of being – weak, compromised – that has caused, given rise to, the propagation of these virtues and hence the good life. Virtue is not the consequence of happiness, but 'happiness' the consequent of virtue. In his own words: "Instead, virtue [as it came to be construed] is itself that slowing down of the metabolism which among other things also brings a long life, numerous progeny, in short Cornarism in its wake.—The church and morality say: 'a race, a people is destroyed by vice and extravagance.' My restored reason says: if a people is destroyed, if it physiologically degenerates, then this is followed by vice and extravagance (i.e. the need for ever stronger and more frequent stimuli, familiar to every exhausted type). This young man grows prematurely pale and listless. His friends say: such and such an illness is to blame. I say: the fact that he fell ill, the fact that he could not withstand the illness, was already the consequence of an impoverished life, of hereditary exhaustion." (Twilight of the Idols, The Four Great Errors – my italics).
In his Genealogy Nietzsche traces the origin of morality not in an attempt to get behind the contextual framework that is constitutive of all human understanding, but rather to identify those frameworks that have come to be constitutive of that very framework but which sneaked in, and were thereby ordained as the bestowers of life itself. They came to have a life of their own, not of the doing of humankind, but of some Omnipotent Power that deifies these; humankind is thereby tussled from her thrown and the Lord's drones follow in her stead. It is now Goodness itself, or the verse of Nature herself, that define aspirations worthy of any man deserving of happiness.
Taking a hammer to this paradigm of thinking, Nietzsche identifies the basic tenet of Stoicism in a longing to cement the good life in living according to Nature, as if there is a determined way and reliable manner in which to ascertain that way. Nietzsche rejects both the naturalism and the rationalism of the Stoics, as I have sketched above. He calls them "self-deluders" because they read their philosophy into an understanding of nature allowing themselves to be tyrannized through the oppression of the otherwise natural proclivity for power by tailoring the passions for a life free of anything "unnecessarily" disquieting. Of course, the general accusation applies to all moralized paradigms which, he says, 'as soon as ever a philosophy comes to believe in itself, it always creates the world in its own image'. Allowing oneself to rest content with any perspective of the world involves, in some shape or form, the deification or the objectification or ossification of that perspective as if it were to speak now and for always for all things! And yet, this is only to delude oneself that the world is how it has been shaped by the mind; and though everything is interpretation (beware those who sit in smug assurances of their perspective! 🙂 ) and hence there is no getting behind or before it, one can adopt an attitude of the diagnostician (for some reason "House" comes to mind both in his method and demeanour – "everybody lies" mostly, delusionally to themselves – looking at all perspectives, from multiple angles – psychological, symptomatic/physiological, social) who looks unnervingly, and unrelentingly from multiple perspectives searching for motives that huddle over pre-conceived perspectives, hammering away at assumptions, presuppositions, and everything that might cunningly conceal these from view (language, habits, fears, desires). The process is itself a state of unrest, of taraxia, that requires courage for 'in all desire for knowledge there is a drop of cruelty'.
So you say, "unhinge me", Pirocacos! Stoics might retort that I have misconstrued and misrepresented the philosophy of their forefathers in that living a eudaimonic life free from unnecessary and irrational preoccupations does not speak to indifference, a rather inhumane attitude to invest in after all. It is rather in acknowledging the causal workings of the universe through attentive rational scrutiny that one is well positioned to deal with unrealized goals, negotiate misfortunes, and endure ensuing suffering. The point is that there is a rational order to the unfolding of Nature that one is well advised to address when engaged in the practice of living life. After all we do live in this natural world and it is constitutive of laws of nature (you wouldn't cajole someone to jump from the 6th floor because it is the fastest route to the College cafe because you know that he'd meet with his death!) and causal forces that one can with varying degree of probability determine in order to better secure the ends. Of course, as I hope I have in outline already made clear, this is to miss the point.
So though the process of deconstruction may appear neurotic and outwardly in disarray, in fact, it is only so perceived by the ill-tempered with a mind to what is apprehended by ageless paradigms and/or those that one holds dear to their heart!