Subject: 
        [evol-psych] ought and is in relation to function
   Date: 
        Mon, 18 Feb 2002 12:56:43 -0600
   From: 
        "Hill, David" 
     To: 
        "'[email protected]'" 




        That an "ought" can be plausibly derived from an "is" can be established as follows.  From (1) my knife is
dull, it can be plausibly derived that (2) my knife ought to be sharpened, given the assumptions that (3) knives are
for cutting and (4)sharp knives cut better than dull ones.  Now, of course, this derivation is not logically bulletproof,
i.e. it is not a logical entailment. (Perhaps I intend to use the knife as a decoration, and therefore do not care how
sharp it is.)  Nonetheless, as inferences go, it is far better than most.  Hume may or may not have been making a
logical point about entailments when he questioned the derivation of ought's from is's.  One thing is clear.  If he
meant to do so, his discussion is drastically incomplete.  For he did not consider whether a teleological or functional
claim like (3) is factual or normative (or both).  Most people who talk superficially about this issue also fail to
consider the status of claims like (3).

        Does it follow from "knives are for cutting" and "sharp knives cut better than dull knives," that "in general, it
is better for knives to be sharp than dull"?  Well, yes it does.  One can claim that this inference depends on the
unstated assumption that it is better that things do what they are for than that they not do what they are for.  I
suppose this could be elicited as a fundamental normative claim without which the conclusion will not follow, but
surely this is a point of no practical importance.  The claim can scarcely be denied, and the inference is solid.

        What this shows is that normative claims (about what is better, about what ought to be done, etc.) follow from
ascertainable empirical facts, plus an appropriate functional claim, plus (perhaps)certain axioms or near-axioms.

        By this route we come to Aristotle's famous question:  "Do human beings have functions (tele)?"  Now I
know that Aristotle is no evolutionist, but his affirmative answer to this question is one with which evolutionists in
general, and evolutionary psychologists in particular, can perhaps find grounds to agree.  Organisms adapt by
finding niches in which they can function well enough to survive and procreate.  Their various organs and instincts
are in large part (though not wholly) adaptive in this sense:  the organ or instinct confers a functional advantage
and therefore an advantage in the struggle for life and descendants.  Thus, most birds function better by flying.  It
would be better for any particular such bird (and, marginally, for his kin and kind) if he can fly.  If humans have
functions/tele, then the same reasoning will apply to us.  It will be better for us if we more efficiently discharge those
functions that we have inherited, functions which for the most part help us survive in the niches our ancestors have
found for us. 

What are those functions?  What exactly is it that we have been doing all these many millennia that allows us to
survive and, latterly, to dominate?  Some of the answers are obvious. We need to relate to one another rationally
and cooperatively, for our mutual benefit. The genetically-based mechanisms that enable us to do this are in part
very obscure, but one thing seems plain.  Getting clearer on human functions promises to help us get clear on the
kind of behavior that is better for us. There is therefore the possibility that evolutionary psychology will have, in a
perfectly reasonable sense of the word, ethical implications.

Caveats:  (i) these implications are not logical entailments; (ii) functions can change and therefore statements
designating them are not eternal truths; (iii) we might wish to train ourselves to behave in ways that run counter to
our instincts.  All of this is true, but beside the main point.  We do not often need entailments.  Much that is
important to know does not have the status of eternal truth.  And how do we know about things like (iii) until we
have researched our own evolutionary heritage and appropriately weighed the competing demands of genetics and
culture?

David Hill