43 - Classified Information: Aristotle's Biology

Aristotle’s scientific outlook is perhaps best displayed in his zoology. Peter looks at his theories of inheritance, spontaneous generation, and the eternity of animal species.

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Further Reading: 

• D. Devereux and P. Pellegrin (eds), Biologie, logique et métaphysique chez Aristote (Paris: 1990).

• A. Gotthelf and J.G. Lennox (eds), Philosophical Issues in Aristotle’s Biology (Cambridge: 1987).

• D. Henry, “Aristotle on the Mechanism of Inheritance,” Journal of the History of Biology 39 (2006), 425–455.

• J.G. Lennox, Aristotle’s Philosophy of Biology (Cambridge: 2001).

• G.E.R. Lloyd, Aristotelian Explorations (Cambridge: 1996).

Devin Henry’s website with several papers on Aristotle’s biology:

Stanford Encyclopedia: Aristotle's Biology

Peter Adamson's picture

Note on this episode

Please note that this is the last episode that will appear until early September -- I am taking a short break in August!

I'd also like here to thank Devin Henry for his help with this episode. Check out his website, listed here in "further reading"!

Louis R.'s picture

Darwin vs. Aristotle

I just listened to the episode pertaining to Aristotle on 'Form and Function' and it appeared to me you were implying that Darwin debunked Aristotle with his theory of Evolution. As I am aware there still remains a debate on the subject matter, (see secular Scientist/Mathematicians David Berlinski's 'The Devil's Delusion'), not to say that life does not evolve through natural selection, but to question it's limitations and/or true potential. That's a side issue really, however it is the core of the theory which I find puzzling, that it's merely a "blind process" of chance with no causal agent. Is that not a philosophical claim rather than a scientific claim? How does science prove this to be a true statement empirically? How does knowing the mechanism of a thing debunk the existence of a causal agent, or tell of it having or not having an end purpose? It doesn't seem, to me at least and I could be mistaken, that Darwin's interpretation of the data is empirical fact and therefore successfully debunks Aristotle's philosophy.

Peter Adamson's picture

Evolution

Thanks very much Louis, this is an interesting issue. What I'd say is that Aristotle denies explicitly that chance could give rise to a natural world that is dominated by regularity, in particular in the case of animals; and that Darwin's theory shows us how chance could do just that. So the thought would be that Aristotle says "here is a phenomenon that could only be explained through non-random causation" and Darwin says "well, here's a way that random causation could give you the same result" -- that counts as a refutation even without doing any empirical research, in the same way that someone might say "there's no way to travel to Jupiter" and then be refuted with an explanation of how it could be done (even without going to Jupiter).

Something else to consider here, though, is whether Aristotle could win the war despite losing the battle. Even if he is wrong about chance, he might be right that natural scientists need to invoke final causation in accounting for animals and other organisms, for instance by saying that the "purpose" of a giraffe's neck is to reach leaves. And one could, as you I think are suggesting, still insist that such purposive language is appropriate even if its presence were explained by a Darwinian genetic account. (Imagine trying to do biology without ever using teleological/purposive language -- would not be easy!) A lot turns here on the question of how robust Aristotle's appeal to final causes is supposed to be -- is he just saying that they need to enter into our explanations or that they are actual items in our ontology, as it were?

Louis R.'s picture

"is he just saying that they

"is he just saying that they need to enter into our explanations or that they are actual items in our ontology, as it were?"

That is a great question, I'm only now researching Aristotle so forgive me of my ignorance, I would assume he believes purpose is ontological, correct?

Peter Adamson's picture

Teleology

Actually the question is one that is hotly disputed in the secondary literature. Some think that the appeal to final causes is "merely explanatory" or "heuristic" -- we need to think of things in terms of purposes but one could also give complete metaphysical account (i.e. give sufficient conditions) by appealing only to formal, material and efficient causes. Some want to say no, the metaphysical causal picture would then be incomplete, and I lean towards that direction but it's a difficult issue.

Peter Lührs's picture

Randam causation in darwinian evolution?

Hello Peter,

first I'd like to say that I've been listening with great interest and pleasure to your series on Aristotle so far, being a student of biology and having a deep interest in Aristotle from that point of view as well as in the broader philosophical perspective.

I have to disagree with you though on the assessment that Darwin's theory of Evolution shows a way how a chance process produces regularity in nature. Actually, the regularity isn't at all explained by the chance process in the theory of evolution in my opinion: The explanatory work that is done in that regard within the Darwinian theory is done by the mechanism of natural selection. And that mechanism is quite the non-random mechanism, as those variations are selected that fit the environment.

In my opinion Aristotle is onto something with his assertion. He is justified to reply to Darwin "but you don't explain the regularity with a random process here." And he could go on about how natural selection is (?) merely a way to say that there needs to be a "purposive" relation between an animal (or any other living being/it's parts) and it's environment, no?

I don't think that one can so easily dismiss Aristotle with appeal to Darwinian evolution.

Regards,
Peter L.

Peter Adamson's picture

Darwin vs Aristotle

Hello Peter,

Thanks for your message and let me congratulate you on your admirable first name. But seriously: I think I agree with you here, at least to some extent. Part of what I wanted to say on the episode (if memory serves... it might actually be something I talk about more in the Empedocles episode) is that Empedocles' proposal is not the same as Darwin's, and that the selection mechanism is what you need to add to randomness to get a proper response to Aristotle. Aristotle is right that invoking a random process, and nothing else, is an inadequate way of getting to the regularities we see. The modern theory of evolution actually adds two things though, namely natural selection and a genetic account of how traits that have been selected are passed on to subsequent generations.

Even then, you would I think be right to resist the idea that evolution shows we should "dismiss" Aristotle because as I think I've also pointed out in the podcasts, it depends on how we understand final causation. It might be that even contemporary biologists would not be able to eliminate talk of purposes in their explanations of nature. Even if there is also a historical account of how purpose-fulfilling traits emerged, this would not make such explanatory talk useless. (That is, we can admit that the giraffe's long nneck is the product of evolution, while still saying that it serves the purpose of allowing it to reach leaves.)

Best wishes,

Peter