It seems obvious to me that morality is always completely subjective. In fact, I think that "morality," as most people still use the term, is not as accurate a term as "moralities."
I think that utilitarianism -- the attempt to provide a rationally-devisible basis for good behavior -- functions primarily, as does religion, as a comforting illusion. A solid guide to correct behavior is posited, referred to as God's will in the one case, and -- what? a utilitarian optimum, in the other? In either case, it is just a matter of discovering what is right.
I, on the other hand, believe that we are all just muddling through, ethically as in so many other ways, and that ethics can never be solved like a mathematical equation. The terms of which the equation is composed are always subjective. Even worse, for utiliatarianism at least, things are always changing. The moral ground under our feet never ceases to shift.
Lest you become too alarmed by my moral relativism, let me say that I believe that I, and the average ultilitarian, and the average believer in God as well, would tend to be very much in agreement most of the time, when judging what we thought was good or bad behavior in given situations, and I think we would also all three tend to agree much of the time that a given situation presents a very difficult choice about what we think should be done. In short, I think that our three distinct individual moralities are probably very similar, although we have arrived at them in three very different ways. Some people hear the phrase "moral relativism" and immediately think of things like the characters in Dostoyevsky who murder people because they are no longer decent Christians, but have become appalling moral relativists with no sense of right and wrong -- and, well, I think Dostoyevsky is overrated.
I think my viewpoint is the most optimistic, the one which allows for the most improvement in behavior. (Although I still insist that said improvement can only be measured subjectively. You may well ask: then how can it really be measured at all? Same way as in the previous paragraph: we would tend to agree or disagree about such things, and we would be kidding ourselves if we thought that there was a more exact way -- or that someone else couldn't define good and bad behavior completely differently and provide his definitions in a utilitarianism with logical frameworks as sound as those in another person's utilitarianism.) I wonder, have you seen the recent film version of Moby Dick,with William Hurt as Ahab, Charlie Cox as Ishmael and Ethan Hawke as Starbuck? It's very good. The scenes of whales being attacked, injured and killed are very disturbing to the contemporary viewer. We are made to sense the animals' suffering quite intensely. And the scenes are even more disturbing in that the whalers' joy at a job well done is communicated just as intimately. So does this make the viewer think that the whalers are bad men? In the case of this viewer, not at all. They remained the very serious men grappling with ethical issues which they had been before the hunts and were again afterwards. The hunting scenes merely reminded me of a great change in moralities which has occurred since the mid-19th century as a result of our knowing much more about whales. Those whalers are muddling through as best they can, just as we today are muddling through, and doing things, probably, without a second thought which would very likely appall our great-great-great-grandchildren, who in turn are doing things which (etc etc etc). Excelsior.