If we define moral progress in brute terms of more and more individuals cooperating, then I think we can cook up a pretty compelling naturalistic explanation for its appearance.

So we know that our basic capacity to form ingroups is adapted to prehistoric ecologies characterized by resource scarcity and intense intergroup competition.

We also know that we possess a high degree of ingroup flexibility: we can easily add to our teams.

We also know moral and scientific progress are related. For some reason, modern prosocial trends track scientific and technological advance. Any theory attempting to explain moral progress should explain this connection.

We know that technology drastically increases information availability.

It seems modest to suppose that bigger is better in group competition. Cultural selection theory, meanwhile, pretty clearly seems to be onto something.

It seems modest to suppose that ingroup cuing turns on information availability.

Technology, as the homily goes, ‘brings…