39 - Form and Function: Aristotle's Four Causes

Posted on 26 June 2011

Aristotle

Aristotle's Physics presents four types of cause: formal, material, final and efficient. Peter looks at all four, and asks whether evolutionary theory undermines final causes in nature.

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Aristotle's Final Cause

Submitted by Bill Harder on Sun, 04/01/2012 - 04:00

Peter,

Your podcasts, lately discovered, are, dare I say, a godsend: well written, well spoken, with just the right dash of levity. Having received but a B.A. in Philosophy more than 30 years ago, I am enjoying this review from a great enough distance to accept the premise that there are no apparent gaps. That is until Lesson 39.

I am somewhat dismayed by your dismissal of Aristotle's final cause. You offer Darwin's theory and genetics as sufficient evidence of the randomness of nature to dispatch the notion of any purpose to life. Your suggestion that design in nature is but apparent begs the question.

Today, many philosophers and scientists seem to reflexively disregard the issue of intelligent design to the point where they become impatient with anyone who questions this self evident truth. Their ability to apprehend this "universal negative" is laudable but I am frustrated that I am not able to comprehend the non-intelligibility of existence and our consequent purposelessness.

Peter, if anything, you have proved yourself patient, both in the preparation of this series and in your careful response to those who offer comments. Can you explain how it is that existence has no final cause or purpose?

While you may say the burden of proof is with me to prove that there are final causes, I would refer to Aristotle's observation of nature. His argument is inductive. I would suggest that it is also demonstrable.

I accept that, from a philosophical, i.e. rational perspective, we cannot determine what the final cause or purpose of a giraffe is. But it does not follow that there is then no final cause or purpose to a giraffe. Again, even though we do not know WHAT that purpose is, there seems to be evidence in its design THAT there is a purpose. I believe that this was the observant Aristotle's main point about final cause.

The further details admitted by later scientific observations do not disprove this point. To argue against Aristotle, it seems that one must either describe the evidence absurdly as "nonintelligent design" or as "intelligent non design." In describing it in your lecture as "apparent design" you seem to be leaning towards the latter position.

I would think that philosophers would be the first to defend the notion of purpose. For if there is no purpose to existence then philosophy is the most meaningless of all intellectual pursuits. All philosophy, including Plato, would be but a footnote to the more practical sciences.

Purpose in nature

Submitted by Peter Adamson on Mon, 04/02/2012 - 07:31

Thanks for this thoughtful post. Maybe I should listen back to what I said in this episode but I think all that I was trying to say is that Aristotle's insistence that regularity cannot be explained through a chance process seems unfounded: Darwinian theories of evolution seem to do precisely that. However, this is a fairly narrow issue about his argument in Physics II.7. More broadly, I think there is good reason to say that we cannot avoid invoking purpose in talking about nature. Leaving aside the debate about intelligent design, it is hard to imagine that biologists could get around saying things like "the giraffe's neck is for the purpose of reaching leaves." If this is right then purposiveness plays an explanatory role in our accounts of nature, but this leaves open the question of how things got to have these purposes (evolution, intelligent design, whatever).

It's perhaps worth noting that Aristotle was not a believer in intelligent design. He did believe in God but his God is not a designer -- that would be Plato's view (albeit that Plato talks of "younger gods" who help the divine craftsman to design lesser entities, for instance the human body). The Aristotelian God is invoked to explain the regular and eternal motion of the heavens, and we are never given even a suggestion that this God put thought into how animals should be structured, or anything like that.

This just goes to show that the question of purposiveness in nature needs to be kept distinct from the question of intelligent design. Darwinian biology and Aristotelian biology can (and do) make free use of "purpose" vocabulary, without either kind of biology ever invoking a superhuman intelligent designer. Thus if we do want to argue for such a designer we need to do more than just point out that nature sometimes seems purposive; further argument is needed, and of course further arguments have been given! (Stay tuned for medieval philosophy...)

Purpose and design

Submitted by Bill Harder on Mon, 04/02/2012 - 19:04

Thank you Peter for both distinguishing and seperating the issues of purposiveness and intelligent design. I do wonder how this seperation would hold up under the rigourous scrutiny of the scholastics. So I will indeed stay tuned and, like Achilles chasing the hare, expect to be on your heels by the time you get to Medieval Philosophy. Then, following at the more leisurly pace of a peripatetic, I hope to find more purpose in your well-designed pods.

evolution of purpose

Submitted by machintelligence on Sat, 04/07/2012 - 01:43

For a lecture on this very topic by my favorite philosopher of science, Daniel Dennett, try:youtube.com/watch?v=3L7uNyQL0H0
(You can skip the first two minutes of introduction,which is dry as dust.) I hope I am not giving away too much by quoting an early critic of Darwin (1868)who claimed his theory was a strange inversion of reasoning: IN ORDER TO MAKE A BEAUTIFUL AND PERFECT MACHINE IT IS NOT REQUISITE TO KNOW HOW TO MAKE IT (caps in the original). I realize that the whole video is over an hour long, but it is well woth watching.

Dennett's Darwinian Design

Submitted by Bill Harder on Fri, 04/13/2012 - 21:10

Thank you for the link to Prof. Dennett's lecture. While I found his distinction between "What for?" and "How come?" interesting, his anecdotal presentation about the evolution of the question "Why?" did not prove his main point that our "intentional stance" is but "a good trick" we play on ourselves.

The professor is indeed following a strange inversion of reasoning in that he seems to mistake a branch of the evolutionary tree for its root. For though the artificer need not know how to make a beautiful and perfect machine in order to produce it, there must at least be someone with a notion of beauty and order to declare it "beautiful and perfect."

Further, by denying any distinction between replication (by external, cyclic forces) and reproduction (by internal self-organizing individuals) Prof. Dennett ignores rather than disproves the argument for purpose. This reduction of the question of final cause to one of efficient cause is itself a pretty neat trick. Dare we suppose it was intentional?

Finally, merely explaining how our interest in the question "Why" might have evolved still leaves the question unanswered. His lecture, while entertaining, in the end appears to lack any true philosophical purpose.