Aristotle, essentialism, and evolution

One of the points of friction between Aristotle’s natural science and modern evolutionary thinking is the idea that Aristotle is committed to essentialism whereas the theory of evolution dissolves any notion of essences. One difficulty in evaluating the claim is that “essence” is exactly the sort of term that Aristotle tried to avoid. When “essence” occurs in an English translation, it is a simplification of an obscure phrase like “the what” or “the what it is” or “the what it was to be”. Even if we say that these phrases all mean “essence” the difference in signification is important: all of Aristotle’s phrases center around the use of the word “what”, which is used (improperly) as a substantive pronoun. As a pronoun, its whole nature is understood in relation to some other nature. “Essence”, however, is a noun pure and simple, and so the mind is not forced to see it in relation to something else. Essence, as a sign, is absolute and what is relative.

When we simply plow through Aristotle’s text changing every “what is” to “essence” we will be prone to fall into exactly the sort of error that is thoroughly discredited by the insights of evolution. In Aristotle’s system, the “what”, when said of a natural thing, refers to a compositeof matter and form; when said of a being without matter thing, it refers to form alone. The first “what” is inseparable from a change and flux so far as it is defined with matter, and so if we say that “the what” means “essence” than the essence of natural things is changeable. Changeability is not the whole of its essence (for form is essential to its essence too) but it is inseparable from it. In this sense of essence, the essences of the things the natural scientist studies are changeable. The difficulty is that “essence”, because of its absolute character, cannot mix with the idea of being changeable. The mind recoils from the idea of “changeable essence” as a contradiction, or at least an extremely poor choice of words. This is why when we find various good reasons to say that essences (or what we thought were essences) are not fixed, it is better to junk the idea of essence altogether. This is fine, but even after we junk the word “essence” we are still left with Aristotle’s “the what”, which, when applied to natural things, includes matter and is therefore capable of change.

Any charge that Aristotle was an “essentialist” has to keep in mind the peculiar notion that he forged of natural essences, sc. ones with matter.  This presence of matter makes natural beings essentially unfixed, changeable, and unintelligible, even though this is not the whole of what we can say about them. There is also a principle by which we can come to know natural things, even to know them as changeable and somehow unknowable.

Now there is obviously a sense in which natural things have an unchangeable essence in Aristotle’s system, sc. so far as they are natural- which for him means so far as they are changeable- their essence is to be composites of matter and form. The theory of evolution, however, takes changeability for granted and so has no use for an account of the essential principles of the changeable as such.


  1. June 27, 2009 at 3:58 pm

    Cool stuff James, I think I almost followed it, too! 😀 (an insult to my poor understanding, not your post!)

    Relevant to the topic of evolution and Aristotle; I just attended a ‘theological meaning of evolution’ conference here in Auckland, NZ, which included a talk from John Owens (Good Shepherd College, Auckland) on “Aristotle, Darwinism and Teleology”.

    He proposed that Paley and Darwin were similar in that they both relied on the artifact analogy (art-ifact –> art-ist), and that neither could account for teleology. Very cool stuff, which you no doubt would have enjoyed.

  2. X-Cathedra said,

    June 27, 2009 at 9:08 pm

    This is a brilliant point. I can think of few things that have muddled the discussion of Aristotle’s (and Thomas’s) approach to the knowledge of corporeal entities than the misunderstanding of essence and its relation to their intrinsic materiality.

    Missing this kind of subtlety has had disastrous consequences. I think of Locke…

    Pax Christi,

  3. July 3, 2009 at 7:25 am

    You make a really interesting point about the unsuitableness of translating as “essence” what is a much more open word.

    I have problems with your second paragraph though. First, you seem to be assuming that “the insights of evolution” include the point that essences as such change–at best that is a **philosophical** interpretation of evolution. There are many other ways of interpreting evolution (in whatever sense it is a complete picture of the development of species), including that one form (in a parent) gives rise to a different form (in the offspring). The Darwinian formulation of evolution, that is, a continuum of forms, is inherently reductionistic and nominalistic (cf.

    Second, I would have expected you to include in support at least a few excerpts from Aristotle showing how the translation “essence” does violence to Aristotle’s intention in the way you claim. I am unaware of Aristotle saying the essence **itself** (or ‘the what’ of a thing **itself**) changes, rather than the **thing** taking on a new essence (“substantial change” in the received parlance). But perhaps you can show me where he does say that?


  4. harvey said,

    July 6, 2009 at 1:31 am

    Beyond the point you are making, which I reserve judgement on, it is with his metaphysics that Aristotle overcomes the essentialist/existentialist dialectic, by inducing Being qua Being.

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