chomsky tends to do this, sometimes: he talks about biology without talking about natural selection. it makes you wonder if he's holding on to some creationist baggage. it might not even be intentional; he might not really realize it. he might also be suffering from the fallacy of descartian dualism, which wants to separate morality from science, even as he identifies it at the start, in some kind of inverted defiance.

bringing in natural selection is the way to make proper sense of what he's saying.

the idea of morality as a genetic faculty is maybe a little undeveloped, but it makes sense if you assign a specific region of the brain to it. i'm not on board with chomsky's ideas of innatism; i'm all about the tabula rasa. but, that means relative to existing structures inside the brain, which are kind of mini-organs. but, then what?

well, then those born with specific tendencies that maximize success of reproduction will be more successful. but, this will depend on different environments. and, we can look at two specific kinds of moralities that have existed in history to see how selection can shape morality.

nietzsche refers to these as master and slave moralities, but they are just as well referred to as nomadic and civilized moralities, respectively. a nomadic society is going to have harsher limits on access to resources that may require it to behave in ways that settled societies may view as barbaric. strong selective pressures may be required to cull free riders from the group. conversely, a civilized society is going to put greater focus on preventing conflict, as it maximizes total gene expression, and resources are plenty, anyways. a moral system in a civilized society should look something like mutual aid. from these two different scenarios, different concepts of morality arise via the process of natural selection.

that does not mean that any system of morals is interchangeable with any other. it means that systems of morals should make sense relative to selective pressures. and, one should then argue that capitalism is incoherent precisely because it is a nomadic system of morals applied to a set of civilized societies. it is a mismatch, and consequently turns the selection on it's head. it is when things get criss-crossed like this that species end up extinct.

i consequently agree with chomsky's position on relativism and foucault, i just wish he had brought in the machinery of natural selection to better present his argument in truly biological terms.