To those who say "Nothing is real," I once replied, "That's great, but how does the nothing work?"
Suppose you learned, suddenly and definitively, that nothing is moral and nothing is right; that everything is permissible and nothing is forbidden.
Devastating news, to be sure—and no, I am not telling you this in real life. But suppose I did tell it to you. Suppose that, whatever you think is the basis of your moral philosophy, I convincingly tore it apart, and moreover showed you that nothing could fill its place. Suppose I proved that all utilities equaled zero.
I know that Your-Moral-Philosophy is as true and undisprovable as 2 + 2 = 4. But still, I ask that you do your best to perform the thought experiment, and concretely envision the possibilities even if they seem painful, or pointless, or logically incapable of any good reply.
Would you still tip cabdrivers? Would you cheat on your Significant Other? If a child lay fainted on the train tracks, would you still drag them off?
Would you still eat the same kinds of foods—or would you only eat the cheapest food, since there's no reason you should have fun—or would you eat very expensive food, since there's no reason you should save money for tomorrow?
Would you wear black and write gloomy poetry and denounce all altruists as fools? But there's no reason you should do that—it's just a cached thought.
Would you stay in bed because there was no reason to get up? What about when you finally got hungry and stumbled into the kitchen—what would you do after you were done eating?
Would you go on reading Overcoming Bias, and if not, what would you read instead? Would you still try to be rational, and if not, what would you think instead?
Close your eyes, take as long as necessary to answer:
What would you do, if nothing were right?
What I am really saying is that the notion of "morality" is so hopelessly contaminated with notions of objective standards and criteria of morality above and beyond humanity that we would do good to find other ways to think and talk about it. But to answer you directly in terms of what I think about the two ways of thinking about morality, I think there is a key difference between (1) "our particular 'morality' is purely a function of our evolutionary history (as it expresses in culture)" and (2) "there is a universal morality applicable to all sentients (and we don't know of other similarly intelligent sentients yet)".
With 1, there is no justification for a particular moral system: "this is just the way we are" is as good as it gets (no matter how you try to build on it, that is the bedrock). With 2, there is something outside of humanity that justifies some moralities and forbids others; there is something like an objective criterion that we can apply, rather than the criterion being relative to human beings and the (not inevitable) events that have brought us to this point. In 1 the rules are in some sense arbitrary; in 2 they are not. I think that is a huge difference. In the course of making decisions in day-to-day existence -- should I steal this book? should I cheat on my partner? -- I agree with you that the difference is academic.
Yes, they're wrong, but I think the important point is "what are they wrong about"? Under 1, the claim that "it is merely a matter of [arbitrary] personal opinion" is wrong as an empirical matter because personal opinions in "moral" matters are not arbitrary: they are derived from hardwired tendencies to interpret certain things in a moralistic manner. Under 2, it is not so much an empirical matter of studying human beings and experimenting and determining what the basis for personal opinions about "moral" matters is; it is a matter of determining whether "it's merely a matter of personal opinion" is what the universal moral law says (and it does not, of course).
I concede that I was sloppy in speaking of "traditional notions", although I did not say that there were no philosophical traditions such that...; I was talking about the traditions that were most influential over historical times in western culture (based on my meager knowledge of ethics based on a university course and a little other reading). I had in mind thousands of years of Judeo-Christian morality that is rooted in what the Deity Said or Did, and deontological understandings or morality such as Kant (in which species-indepedendent reason compels us to recognize that ...), as well as utilitarianism (in the sense that the justification for believing that the moral worth of an action is strictly determined by the outcome is not based on our evolutionary quirks: it is supposed to be a rationally compelling system on its own, but perhaps a modern utilitarian might appeal to our evolutionary history as justification).
On the topic of natural law tradition, is it your understanding that it is compatible with the idea that moral judgments are just a subset of preferences that we are hardwired to have tendencies regarding, no different in kind to any other preference (like for sweet things)? That is the point I'm trying to make, and it's certainly not something I heard presented in my ethics class in university. The fact that we have a system that is optimized and pre-configured for making judgments about certain important matters is a far cry from saying that there is an objective moral law. It also doesn't support the notion that there are moral facts that are different in kind from any other type of fact.
It seems from skimming that natural law article you mentioned that Aquinas is central to understanding the tradition. The article quotes Aquinas as 'the natural law is the way that the human being âparticipatesâ in the eternal law' [of God]. It seems to me that again, we are talking about a system that sees an objective criterion for morality that is outside of humanity, and I think saying that "the way human beings happened to evolve to think about certain actions constitutes a objective natural law for human morality" is a rather tenuous position. Do you hold that position?