Friday, October 02, 2009

On various kinds of purpose

There are I think four different ideas that we might be implying when we talk about the purpose for something. One of them is an intended purpose. The purpose of X is Y because the one who made X intended it to do Y. If we believe in God, we probably believe in this kind of a purpose for ourselves. The second is natural purpose, so that the nature of something drives it toward a certain goal. We are sometimes told that the purpose of sex is reproduction, because that is its natural consequence. Thirdly, there is a chosen purpose. I choose to pursue the goal of becoming and airline pilot of a concert pianist because that is what I want to become. Finally, there is Darwinian purpose. If you believe in evolution, you believe that creatures have certain characteristics because those characteristcs helped them survive and pass on their genes. So a thoroughgoing Darwinian will say that the purpose of your eyes is to see, not because someone planned them so you could see, but because creatures who developed eyes had better awareness of the environment than the creatures they were competing with, and this resulted in those creatures surviving.


Mariano said...

Good muse.
I have found it useful to draw similar distinctions between "meaning" and "purpose."
Meaning being extrinsic and purpose being intrinsic.
For example, a baseball bat has a purpose--to hit a ball--but only has meaning if it is given one--Babe Ruth gave it to my father.

I mused further on this here (if it is of interest):

Joshua said...

Are natural and darwinian purpose really distinct? Or am I falling into some mental trap by thinking them the same?

kbrowne said...

I think Joshua is right. Of course I may be falling into the same mental trap. But surely reproduction is the Darwinian purpose of sex. Can you give an example of a natural purpose that does not fall into one of the other categories?

Victor Reppert said...

I was thinking more of an Aristotelian natural purpose rather than a Darwinian one. Of course the Aristotelian conception is a difficult one because you have the theistic tradition pushing it in the direction of intended purpose, and the Darwinian materialist tradition pushing it in the direction of Darwinian function.

But I think something can have an intended purpose without that purpose resulting in the fulfillment of the creaturely nature. If Calvinism is true, it is the intended purpose of some people to provide God the opportunity to display his wrath against sin and to serve as object lessons to make sure everyone up in heaven knows that they got there by grace, but in fulfilling that divine purpose, their desires are everlastingly frustrated. Or, to take a simpler example, we raise some animals for food. Sometimes we do in a way that pays attention to their interests (kosher laws suggest this way of thinking) and sometimes people simply exploit the animals, as in the case of veal calves cooped up in tiny pens. So I think we need the idea of an inner purpose that involves the fulfillment of the nature of the created object.

I an inclined to think that a concept of love could be developed as an active desire for the fulfillment of another being. X loves Y just in case X wants Y to fulfill itself, and does whatever is possible (consonant with other moral duties X might have) to make it possible that Y fufills itself.