Thursday, March 31, 2011

Tigers, snakes, morals and evolution

Case 1: Your ancestors evolved (genetically or mimetically) a belief that a local forest was full of tigers. This belief has kept your ancestors out of the forest where they would have been eaten by tigers, and that is why the belief evolved.

Case 2: Your ancestors evolved a belief that a local forest was full of tigers. This belief has kept your anceestors out of the forest where they would have been killed by snakes and that is why the belief evolved—a belief in tigers, let us suppose, is better at keeping people away thant a belief in snakes. Coincidentally, the forest is full of tigers, but these tigers are shy—they silently run away when people approach, and no one has ever had an encounter with one.

If Case 1 is a case of knowledge, Case 2 is a Gettier case, and hence not a case of knowledge that the forest is full of tigers. And if Case 1 is not a case of knowledge, Case 2 isn't either. So, either way, Case 2 is not a case of knowledge.

Case 3: Your ancestors evolved moral beliefs. These beliefs kept social cooperation going and that's why they evolved. The beliefs are by and large true.

In Cases 2 and 3, unlike in Case 1, there is no relevant connection betweeen why your ancestors evolved the belief and the belief's truth. Case 3 is relevantly like Case 2: it is not a case of knowledge but at most of Gettiered justified true belief.

A story like Case 3 is the only plausible account of the genesis of moral belief available to the non-Aristotelian naturalist. Since we do know moral truths, mon-Aristotelian naturalism is false. Can the Aristotelian do better? Maybe. Moral truth is grounded in natural human inclinations, she can say, and the same inclinations often give rise, noncoincidentally, to correct moral beliefs. I wonder if the only way for a naturalist to be a realist about morality is for her to be an Aristotelian.

3 comments:

Alexander R Pruss said...

Let me situate this argument a little. I think the best responses to Plantinga's EAAN were ones that depended on the idea that given naturalism we would expect our senses to evolve in such a way as to be responsive to the physical facts outside of us. We can expect that our visual sense of tigers should be responsive to the presence of tigers. But no parallel move can be made by the non-Aristotelian naturalist in the moral claim--our moral sense cannot then be responsive to the moral facts, because if non-Aristotelian naturalism is true, moral facts do not enter into causal relations.


Interestingly, the theist or the Aristotelian can hold that moral facts do enter into causal relations. Our natures enter into causal relations, and so if, as the Aristotelians say, moral facts are grounded in our nature, it is quite possible that moral facts enter into causal relations (maybe that in our nature which grounds the requiredness of gratitude impels us to feel a desire to be grateful). And if moral facts are grounded in the nature of God, well that same nature is causally behind our existence--God, who is identical with his nature (according to divine simplicity; or at least whose actions are informed by his nature), causes us to exist.

Mike A Robinson said...

Professor Pruss:
Another fascinating post, I so often enjoy your blog.
You stated: “Maybe. Moral truth is grounded in natural human inclinations, she can say, and the same inclinations often give rise, noncoincidentally, to correct moral beliefs. I wonder if the only way for a naturalist to be a realist about morality is for her to be an Aristotelian.”

Does the idea that “inclinations often give rise … to correct moral beliefs,” assume or rely on an absolute standard of moral beliefs; a standard that defines that which is correct?
If so is there a possible escape for the Aristotelian naturalist?

Nightvid said...

Your argument is pre-supposing that morality is not identical to the benefits of empathy and cooperation. This is a Hidden Premise Fallacy and your argument is unsound...