Phl 303
Lecture 11: Darwin


Today's Lecture: Darwin

Three Questions:

  1. Did Darwin Bury Aristotle or Resuscitate Him?
  2. Is there a Difference of Kind or only of Degree between Humans and Other Animals?
  3. Is Human Nature Constant and Permament, or in Continual Flux?

1. Darwin and Aristotle on Final Causation (built-in purposes, natural functions)

Philosophers and Biologists have argued both ways:

A. Darwin Buried Aristotle

Assume: that biological systems have built-in purposes only if they have been specifically designed by God to serve those purposes.

Then, Darwinism provides a basis for denying the existence of any built-in purposes in the biological world, since it replaces specific Divine designs with the actions of an impersonal, purely physical process, namely, natural selection.

Dawkins: design vs. designoids.
Organisms only appear to have been designed; they are really "designoids".

Contrast:
Mt. Rushmore: design.
Mountain in NM that resembles JFK: designoid.

Some materialists, especially in Germany, reached this conclusion. Marx attempted to dedicate Das Kapital to Darwin.

B. Darwin Resuscitated Aristotle.

Correspondence between Asa Gray (leading American zoologist) and Darwin.

Gray:
"We recognize the great service rendered by Darwin to natural science by restoring teleology to it, so that instead of having morphology against teleology, we shall have henceforth morphology married to teleology." Nature, June 4, 1874.

Darwin responds:
"What you say about teleology pleases me especially, and I do not think anyone else ever noticed the point. I have always said that you were the man to hit the nail on the head." (quoted in Autobiography, p. 308)

Francis Darwin:
"One of the great services rendered by my father to the study of Natural History is the revival of Teleology. The evolutionist studies the purpose or meaning of organs with the zeal of the older Teleologist, but with far wider and more coherent purpose." Echoed by Thomas Huxley. (Auto., p. 316)

Assume that final causation/natural purpose does not necessarily involve being the product of an intentional design.
Case in point: Aristotle believed that organs had purposes, even though he did not believe that they had been designed.

We can use natural selection to distinguish function/use, essence/accident.

Ask: what did natural selection select this organ for?

Example:
The heart does all of the following:

Why did natural selection favor creatures with a heart?
Because hearts pump blood, and not for any reason related to the other facts.

Some recent philosophers have gone so far as to say that only natural selection can produce things with final causes, purposes.

Seems to go too far: surely purposes can result from either natural selection or intelligent design.

As philosophers, we don't have to settle the Darwinism/creationism issue, since both agree that final causation applies to biological systems.

2. Is there a Qualitative or merely a Quantitative Difference between Humans and Other Animals?

Darwin consistently answers: only a difference of degree, of quantity.

What makes humans unique?

Darwin argues that many of these have precursors in non-human animals.
He deals in detail with the first three.
Morality is species-relative.

Morality is based on:

  1. Instinctive sympathy.
  2. Sensitivity to praise and blame by others.
  3. Habit.
The universal morality of good will to all is an accidental by-product of the expansion of human reason and imagination, working on these raw materials.

Talks of "higher" and "lower" standards of morality -- apparently with reference to some transcendent, extra-biological reference point.

3. Is Human Nature a Constant, or in continual Flux?

Darwin believed in flux: an ongoing state of gradual, essentially constant change.

Contrast: punctuated equilibrium.
Long periods of stasis, punctuated by brief, rapid episodes of change.

The continual flux version has a number of implications:

  1. Human Nature can and does change over time. Aiming at a moving target.
  2. We can produce (both intentionally and unintentionally) changes in human nature.

    Raises the issue of eugenics, and of genetic re-engineering.

    Discussion in DOM on the impact of civilization on course of human evolution.

  3. Different sub-populations, races may have different versions of human nature.

    As the whole population moves through phylogenetic space, different sub-populations may be moving at different velocities, in different directions.

    Raises questions about the unity of human species.


Last updated October 13, 1998
Created by: Robert C. Koons
Send comments to: koons@la.utexas.edu

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