Eve speaks of the Objectivist “Birthday Cake of Existence,” according to which metaphysics is the base, and epistemology, ethics, politics, aesthetics are piled on in that order. Other than aesthetics, this is right! My former teacher Michael Devitt likes to say, “Put metaphysics first!” And that's key. Metaphysics is the study of what there is. Well, what is there? There are rocks, cats, trees, and so forth, which we know from ordinary experience. Science tells us what else there is: genes, quanta, and so forth. That's where we start, with our list of stuff drawn from common sense and science.
But isn't epistemology really first? I mean, how do we know that we know that there are rocks, cats, and trees? Well, we do know. That's the data for an epistemology. If your epistemology implies that we don't know that there are rocks, trees and cats, so much the worse for your epistemology. Roderick Chisholm distinguished between particularism and methodism in epistemology. Descartes and Hume are the paradigm methodists. They came up with pretty abstract theories, that is, methods for determining what would count as knowledge, and then went on to see what putative knowledge could clear their theoretical hurdles. Turns out, not much! Thomas Reid, the Rodney Dangerfield of Modern epistemologists (and the paragon of particularism), rightly pointed out that folks like Descartes and Hume pretty clearly had to claim to know that their epistemological theories were true. But are Cartesian and Humean epistemological assumptions really on firmer ground than the existence of cats? Well, no. There are cats. If your epistemology can't handle cats, then it isn't worth a bag of hair.
But how about genes, protons, synapses and the like? That's trickier than common sense knowledge. Why should we think we know that such funny mostly invisible things are part of the Inventory of the World? Well, we slide into a bit of unsophisticated epistemology to figure out some of our metaphysics. The best argument for scientific entities is the argument from predictive and technological success. Our theories that posit these things have made us successful in predicting and controlling the world. The best explanation for that success is that those theories are pretty much right.
So, we've got out list. But we've also got more. We include scientific entities on our list, because they account for predictive & technological success. But how did we find out about them? Science! Now, it's pretty incredible this success of science. And science is a way of knowing stuff, like what exists. So, like Quine, we should regard science as the knowledge gathering enterprise par excellence. Now science, it turns out, is going to tell us lots of things about the way our minds process information, and what kinds of cognitive mechanisms produce reliable belief. And this knowledge can be turned around to improve science, which improves our knowledge about how our minds gain knowledge, and so on and so on.
Now, Eve pretty much suggests that we should be a kind of epistemic particularists about ethics. Maybe we should start with a list of things we know are wrong, like killing babies, and use the items on the list as constraints for the adequacy of our ethical theories. Isn't a moral theory that can't account for the absolute wrongness of baby-killing like an epistemological theory that can't account for cats — not worth a box of mulch? I don't think so!
In order to be secure in the parallel, we'd have to know that the data we derive from ethical intuition derive from mechanisms of belief formation as reliable as the processes that lead us to believe that there are cats. But we have good reason to think the opposite! That the mechanisms of ethical belief formation aren't truth tracking, because truth tracking isn't really their function. In the ancestral evolutionary environment, we certainly needed mechanisms that would inform us of the presence of cats, lest the cats eat us. So it is not surprising that most brain-heavy species have very reliable mechanisms for ascertaining the existence of things like cats, and for categorizing those things with more or less precision.
But what's moral intuition good for? We'll it's good for jiggering with the payoff matrices for social choices in order to promote fitness enhancing moves in social games. Built-in visceral baby protectiveness is a damn good way to protect your next-generation gene vehicles. Visceral anti-incest sentiments are a good way not to waste perfectly good germs cells, and so on. But I think we might do well question whether we need to take the wrongness of incest, say, as a datum for moral theory, since the reasons that incline us to confidently regard it as wrong have nothing much to do with morality.
So, no, we should not be particularists in moral theory. We really do have to develop a general method for determining what things count as right and wrong, largely independent of our intuitions about it. Now, I think morality is, on the personal level, about having a happy, satisfying, meaningful live, and, on the social level, morality amount to a “cooperative endeavor for mutual advantage”. Basically, I'm stipulating that this is what morality is about, although I do think it captures a great deal of what we intuitively take morality to be about. If you don't want to call this morality, then that's fine. It's up to you. But then we might wonder why we ought to care about morality, so construed.
What we have to find out about it what it really means to have happy, satisfying, meaningful lives, and what is necessary to facilitate effective cooperation for mutual advantage. Religion and tradition may help us to some extent, by pointing to emergent solutions to the problems of living. But we should not rely on it. The work for morally serious people is in discovering how human beings mentally represent alternatives courses of action and payoff structures, how they learn and act on cultural norms, how institutional structures relate to socially norms and provide incentives that result in beneficial patterns of behavior. What's happiness, really? How do we best achieve it, given our biological nature and socio-historical condition? This is, as David Gauthier put it, “morality for adults, for persons who live consciously in a post-anthropomorphic, post-theocentric, post-technocratic world.”