Christopher Shea, in the Chronicle of Higher Education, writes an essay on Ms Churchland's ethical thinking and the importance she attaches to neurochemicals as a biological basis for our moral decision-making. Shea says this about Churchland's views:
Oxytocin's primary purpose appears to be in solidifying the bond between mother and infant, but Churchland argues—drawing on the work of biologists—that there are significant spillover effects: Bonds of empathy lubricated by oxytocin expand to include, first, more distant kin and then other members of one's in-group. (Another neurochemical, aregenine vasopressin, plays a related role, as do endogenous opiates, which reinforce the appeal of cooperation by making it feel good.)It's all very interesting, but what might have been emphasized a bit more in Shea's piece is that what Churchland and others in her camp are doing is reducing morality to a mere illusion. This is, indeed, what all naturalistic attempts to explain the moral sense wind up doing. Shea quotes one colleague of Churchland's who admits as much:
From there, culture and society begin to make their presence felt, shaping larger moral systems: tit-for-tat retaliation helps keep freeloaders and abusers of empathic understanding in line. Adults pass along the rules for acceptable behavior—which is not to say "just" behavior, in any transcendent sense—to their children. Institutional structures arise to enforce norms among strangers within a culture, who can't be expected to automatically trust each other.
These rules and institutions, crucially, will vary from place to place, and over time. "Some cultures accept infanticide for the disabled or unwanted," she writes, without judgment. "Others consider it morally abhorrent; some consider a mouthful of the killed enemy's flesh a requirement for a courageous warrior, others consider it barbaric."
Duke's Owen Flanagan Jr. defends this highly pragmatic view of morality. "Where we get a lot of pushback from philosophers is that they'll say, 'If you go this naturalistic route that Flanagan and Churchland go, then you make ethics merely a theory of prudence.' And the answer is, Yeah, you kind of do that. Morality doesn't become any different than deciding what kind of bridge to build across a river. The reason we think it makes sense is that the other stories — that morality comes from God, or from philosophical intuition — are just so implausible."This is surely correct. If the "God hypothesis" is implausible then morality is just chemical reactions in the brain, and decisions about whether to help one's fellow man or kill him are no different than decisions about whether or not to build a bridge across a river.
As we've argued here on previous occasions, one who holds to this view must perforce embrace some form of ethical subjectivism, and the most compelling candidates are egoism or nihilism.
If helping the poor gives you an oxytocin high, well, then do it. If ignoring the needs of others in order to advance your own welfare is what elicits the flow of neurochemicals then it's not wrong to do so. There's no reason to think treating others cruelly or selfishly is anything more than behavior some find rewarding and others find distasteful. Like putting mayonnaise on a peanut butter sandwich, it's neither right nor wrong, it's just a matter of taste.
I wonder whether Ms Churchland has followed her convictions to their logical conclusion and forswears all moral judgments about other peoples' behavior, which, indeed, she must do if she believes that morality is just the percolations of chemicals through neurons. I wonder if she really looks at sex trafficking, torturing for amusement, and the long-term destruction of our planet as simply cases of different strokes for different folks.
Perhaps, but I doubt it. The only people who call themselves materialists who actually live as though they really believed materialism is true are nihilists and egoists, and Ms Churchland strikes me as neither.