The heart of my title essay in “Against the Men of the Crowd” is the marshaling of Epicurean texts in support of a single thesis: that the key foundational insight of Epicurus was to identify the error in relying on an unreal tool of thinking (fictional access through religion or logic to ideal concepts) rather than on a real tool (the triad of three faculties given us by Nature – senses, anticipations, and pain/pleasure.) At hazard of overstating the case, I would submit that the validity or invalidity of all Epicurean philosophy, including not only the Physics but also the Ethical conclusions we value so highly, rests on whether Epicurus was correct in his frontal attack on reasoning based on ideal concepts not accessible to the senses.
Let me add is support of this thesis some analysis of the same error by someone far more intelligent than your humble webmaster: Friedrich Nietzsche, from an essay found here, on Parmenides, who preceded and influenced the thought of Plato and the Stoics. The entire essay is interesting, but I want to direct your attention to two of Nietzsche’s concluding paragraphs, and especially the part I have highlighted, which I believe are helpful in understanding Epicurus’ position:
The prelude in Parmenides’ philosophy is played with ontology as its theme. Experience nowhere offered him being as he imagined it, but he concluded its existence from the fact that he was able to think it. This is a conclusion which rests on the assumption that we have an organ of knowledge which reaches into the essence of things and is independent of experience. The content of our thinking, according to Parmenides, is not present in sense perception but is an additive from somewhere else, from an extra-sensory world to which we have direct access by means of our thinking. Now Aristotle asserted against all similar reasoning that existence is never an intrinsic part of essence. One may never infer the existentia of being from the concept being-whose essentia is nothing more than being itself. The logical truth of the pair of opposites being and nonbeing is completely empty, if the object of which it is a reflection cannot be given, i.e., the sense perception from which this antithesis was abstracted. Without such derivation from a perception, it is no more than a playing with ideas, which in fact yields no knowledge. For the mere logical criterion of truth, as Kant teaches it, the correspondence of knowledge with the universal and formal laws of understanding and reason, is, to be sure, the conditio sine qua non, the negative condition of all truth. But further than this, logic cannot go, and the error as to content rather than form cannot be detected by using any logical touch-stone whatever. As soon as we seek the content of the logical truth of the paired propositions “What is, is; what is not, is not,” we cannot in-deed find any reality whatever which is constructed strictly in accordance with those propositions. I may say of a tree that “it is” in distinction to things which are not trees; I may say “it is coming to be” in distinction to itself seen at a different time; I may even say “it is not,” as for example in “it is not yet a tree” when I am looking at a shrub. Words are but symbols for the relations of things to one another and to us; nowhere do they touch upon absolute truth. Above all, the word “being” designates only the most general relationship which connects all things, as does the word “nonbeing.” But if the existence of things themselves cannot be proved, surely the inter-relationship of things, their so-called being or nonbeing, will advance us not a step toward the land of truth. Through words and concepts we shall never reach beyond the wall of relations, to some sort of fabulous primal ground of things. Even in the pure forms of sense and understanding, in space, time and causality, we gain nothing that resembles an eternal verity. It is absolutely impossible for a subject to see or have insight into something while leaving itself out of the picture, so impossible that knowing and being are the most opposite of all spheres. And if Parmenides could permit himself, in the uninformed naivete of his time, so far as critique of the intellect is concerned, to derive absolute being from a forever subjective concept, today, after Kant, it is certainly reckless ignorance to attempt it. Now and again, particularly among badly taught theologians who would like to play philosopher, the task of philosophy is designated as “comprehending the absolute by means of consciousness,” even in the form of “The absolute is already present, how could it otherwise be sought?” (Hegel) or “Being must be given to us somehow, must be somehow attainable; if it were not we could not have the concept.” (Beneke) The concept of being! As though it did not show its low empirical origin in its very etymology. For esse basically means “to breathe.” And if man uses it of all things other than himself as well, he projects his conviction that he himself breathes and lives by means of a metaphor, i.e., a non-logical process, upon all other things. He comprehends their existence as a “breathing” by analogy with his own. The original meaning of the word was soon blurred, but enough remains to make it obvious that man imagines the existence of other things by analogy with his own existence, in other words anthropomorphically and in any event, with non-logical projection. But even for man-quite aside from his projection–the proposition “I breathe, therefore being exists” is wholly insufficient. The same objection must be made against it as must be made against ambulo, ergo sum or ergo est.
The second concept, of more content than being, likewise invented by Parmenides though not used by him as skillfully as by his disciple Zeno, is that of the infinite. Nothing infinite can exist, for to assume it would yield the contradictory concept of a perfect infinity. Now since our reality, our given world, everywhere bears the stamp of just such perfect infinity, the word signifies in its very nature a contradiction to logic and hence to the real, and is therefore an illusion, a lie, a phantasm. Zeno especially makes use of indirect proof. He says, for example, “There can be no movement from one place to another, for if there were such movement, we would have a perfect infinity, but this is an impossibility. Achilles cannot catch up with the tortoise which has a small start over him, for in order to reach even the starting point of the tortoise, Achilles must have traversed innumerable, infinitely many spaces: first half of the interval, then a fourth of it, an eighth, a sixteenth, and so on ad infinitum. If he in reality does catch up with the tortoise, this is an un-logical phenomenon, not a real one. It is not true Being; it is merely an illusion. For it is never possible to finish the infinite.” Another popular device of this doctrine is the example of the flying and yet resting arrow. At each moment of its flight it occupies a position. In this position it is at rest. But can we say that the sum of infinitely many positions of rest is identical with motion? Can we say that resting, infinitely repeated, equals motion, which is its contrary? The infinite is here utilized as the catalyst of reality; in its presence reality dissolves. If the concepts are firm, eternal and existent (remembering that being and thinking coincide for Parmenides), if in other words the infinite can never be complete, if rest can never become motion, then the arrow has really never flown at all. It never left its initial position of rest; no moment of time has passed. Or, to express it differently: in this so-called, but merely alleged reality, there is really neither time nor space nor motion. Finally, even the arrow itself is an illusion, for it has its origin in the many, in the sense-produced phantasmagoria of the non-one. Let us assume that the arrow has true being. Then it would be immobile, timeless, uncreated rigid and eternal-which is impossible to conceive. Let us assume that motion is truly real. Then there would be no rest, hence no position for the arrow, hence no space-which is impossible to conceive. Let us assume that time is real. Then it could not be infinitely divisible. The time that the arrow needs would have to consist of a limited number of moments; each of these moments would have to be an atomon–which is impossible to conceive. All our conceptions lead to contradictions as soon as their empirically given content, drawn from our perceivable world, is taken as an eternal verity. If absolute motion exists, then space does not; if absolute space exists, then motion does not; if absolute being exists, then the many does not. Wouldn’t one think that confronted with such logic a man would attain the insight that such concepts do not touch the heart of things, do not undo the tangle of reality? Parmenides and Zeno, on the contrary, hold fast to the truth and universal validity of the concepts and discard the perceivable world as the antithesis to all true and universally valid concepts, as the objectification of illogic and contradiction. The starting point of all their proof is the wholly unprovable, improbable assumption that with our capacity to form concepts we possess the decisive and highest criterion as to being and nonbeing, i.e., as to objective reality and its antithesis. Instead of being corrected and tested against reality (considering that they are in fact derived from it) the concepts, on the contrary, are supposed to measure and direct reality and, in case reality contradicts logic, to condemn the former. In order to impose upon the concepts this capacity for judging reality, Parmenides had to ascribe to them the being which was for him the only true being. Thinking and that single uncreated perfect globe of existentiality were not to be comprehended as two different types of being, since of course there could be no dichotomy in being. Thus an incredibly bold notion became necessary, the notion of the identity of thinking and being. No form of perception, no symbol, no allegory could help here; the notion was utterly beyond conceiving, but-it was necessary. In its very lack of any and all possibility for being translated into sensation, it celebrated the highest triumph over the world and the claims of the senses. Thinking and that bulbous-spherical being, wholly dead-inert and rigid-immobile must, according to Parmenides’ imperative, coincide and be utterly the same thing. What a shock to human imagination! But let their identity contradict sensation! Just that fact guarantees better than anything else that this was a conception not derived from the senses.