It is my belief that human beings live in an a-moral world, wherein each of us acts only on our own behalf; in the interrest of what we think is "good" or against what we think is "bad." I think that each of us can be certain that we exist (cogito ergo sum) but that we can and do doubt all else.* I believe that each of us operates by our own laws, and that we disregard the laws, norms and common sense of society when it suits us. Essentially, we are subjectively moral; we are moral relativists.
I do, however, think we have evolved to personally want, or enjoy, behaviors that often benefit larger society because groups tend to survive better than individuals, and so those of us who happen to personally enjoy that which benefits a collective are more likely to survive to pass on those preferences. Here is an example, from yesterday's news, of what I mean:
An Ohio man who needs kidney dialysis to stay alive won $5 million in the lottery--but says he plans on giving part of his windfall away. "I'm going to help people because I love it. It makes me feel good, and I think that's what God put us here for," Phillip Withem of Logan said Tuesday, right after accepting the mega-check from the Ohio Lottery.
Notice that the motivation for doing good for others is never that someone else thinks it's good, but that the individual doing it thinks it is good, or enjoys it (at least not that I've ever heard).
* I have given many examples of why I think we can doubt all else, on previous posts here on A.N. Among them have been the dream argument, which is nicely summed up with the question 'What evidence do you have that you are not dreaming right now?' This argument remains an unsolved basis of doubt for all evidence beyond one's own existence. (If you have a refutation for this argument, the philosophical world would be very interrested in your proof)
The only thing one cannot doubt is one's existence because doubt requires thought, which has qualia we cannot avoid feeling when we engage in it. Existence is that which has qualia, so that the very act of doubting one's existence proves it. This is the assertion behind DesCartes' line cogito ergo sum, and is the basis for subjective knowledge. There remains no proven basis, however, for objective knowledge, which means morality between individuals is an illusion. (And again, if you have proof for any further assertion than your own existence, the philosophical world wants to hear it).
Question? Comments? Refutations?