Suppose an atheist advanced the following line of thought:
"The Universe must have a cause for its existence. The only thing capable of causing the Universe to exist is a deity of some kind. However, it is impossible to disprove the proposition that a deity of some kind exists. Hence, it is not a scientific theory and so I need not worry about it."
We would clearly see this as a silly way of thinking. (I do not intend this reasoning as a defence of the causal argument for God's existence, but rather as an illustration). And yet my own "thought" regarding determinism has been rather similar for a while. Something like:
"Assuming we accept that events cause other events, it seems obvious that pretty much any event can be traced backwards through time as the natural consequence of the previous state of the world. That is to say, given the exact positions and velocities of all particles in the universe at one point in time, you could in principle predict the exact future of the universe. Thus, everything that happens, has happened, and is yet to happen, was set in stone from the very beginning of the universe. However, it is impossible to disprove this, since one can always say of any experimental data 'Oh, that's how it must have been set to happen given the prior state of the universe,' regardless of the results. Thus determinism is not a scientific theory, which I may therefore avoid worrying about."
To be fair to myself, I don't think I was ever particularly happy with this. It entails a blatant ignorance of the difference between epistemological methods and metaphysical truth. I would happily admit that this "thinking" was motivated by a desire to believe in free will and therefore to preserve a notion of ethics, combined with an honest rejection of compatabilist views of determinism and free will. Indeed, it would be dishonest to pretend that I will believe pretty much anything if it allows me to preserve ethics. However, I'm moving towards the idea that perhaps ethics is possible without free will. I see two ways in which this might be true. There may well be more, which I have missed; indeed, neither truly satisfies me.
1: Moral identity
When put in identical situations, different people will make different choices. This is because they are different people. When we pass moral judgement, we judge not the action but the person doing the action; the action is simply evidence towards the moral nature of the agent.
2: "Non-judgemental Consequentialism"
The morality of an action may be judged entirely by its consequences. Since the sets of consequences may be ordered in terms of their preferability, so may the actions themselves. Note, however, that since the agent's actions were pre-determined, they cannot actually be judged for their actions; this is therefore a somewhat narrower theory than standard consequentialism.
What implications might these theories have? Moral identity as a system is heavily at odds with my Christian belief - after all, one of the most fundamental tenets of Christianity is that we are not and cannot be saved by our own works or goodness, but are entirely reliant upon Christ and his death for us. The phrase "love the sinner, hate the sin" comes to mind as a principle in pretty much exact opposition to this theory. However, this may salvage a way of constructing ethics for those of a different background. One potential problem for the theory would be how to judge people doing wrong who genuinely believe themselves to be doing right. Let us assume that, in carrying out the Holocaust, Hitler genuinely believed himself to be doing what was morally good. Under a standard view of morality, we could say, "Yes, he believed himself to be doing right, but he was disastrously mistaken, and was in fact doing wrong." Under this "Moral Identity" theory, it becomes a lot harder to reconcile actions which seem obviously wrong with someone who genuinely believes themselves to be doing good.
What then of "non-judgemental consequentialism"? Well, this faces all the usual problems of consequentialist and utilitarian views of morality. But also, the idea of a world where actions are objectively good and bad, yet you cannot be praised for doing good nor criticised for doing bad seems completely alien. It would be like an action film in which the hero saved the entire world, everyone knew that he had done this (at great personal cost, no less!) and yet when he returned home, he did not receive the slightest bit of congratulations or thanks. This is not to say that it is wrong, merely that it would only make sense from a distinctly non-human perspective. Coming from a Christian background, the fact that the logic behind it is deeply counter-intuitive and requires a non-human set of intuitions seems like it should be evidence in its favour. The lack of moral judgement doesn't necessarily contradict Christian theology - after all, it is not our own morality which gets us into heaven. The key problem from a Christian perspective seems to be that the removal of any notion of moral judgement also seems to make thankfulness irrelevant, yet God is thanked many times, not only by fallible humans but by heavenly creatures and, of course, by Jesus himself.
So what then are my options?
1) Find a good reason to reject determinism, which leaves open the possibility of objective ethical judgement
2) Give up on objective ethical judgement
3) Adopt an extreme version of utilitarianism which precludes judgement of people
4) Find a new way in which determinism could be consistent with objective ethical judgement
The search for my chosen moral system continues...