J. David Velleman has posted How We Get Along on the web. Velleman describes this as "A series of five lectures on metaethics." Here are the first two paragraphs:
What difference does it make in our attitude toward someone, or what difference should it make, that we recognize him as a rational agent? Different answers to this question issue from different conceptions of rational agency. According to the decision-theoretic conception, the recognition of someone’s rational agency should lead us to act in ways that maximize an expected-utility function reflecting how he is likely to act in maximizing an expected-utility function reflecting how, from his perspective, we seem likely to act. According to Kant, the recognition of someone’s rational agency should lead us to treat him as embodying something that our own rational agency commits us to respect, by treating it never merely as a means but always also as an end in itself.
I want to explore how the same question would be answered by a different conception of the rational agent. It’s a conception that I have formulated in various ways at various times in the past,1 but for present purposes, I want to explore a particular formulation that I have not fully explored before.2 This formulation is especially hospitable to my present question, which is how rational agents should view one another. Eventually, in subsequent lectures, this question will lead me into the nature of morality, considered as a product of the interactions among rational agents. The main subject-heading for these lectures is thus metaethics, but I will begin, in vaguely Kantian fashion, with rational agency.
Highly recommended! Velleman is one of the very best.