‘In 1989 I was invited to go to Los Angeles in response to a request from the Dalai Lama, who wished to learn some basic facts about the brain.’

Besides being my own selection for ‘name drop of the year’, this remark from Patricia Churchland’s new book Conscience perhaps tells us that we are not dealing with someone who suffers much doubt about their own ability to explain things. That’s fair enough; if we weren’t radically overconfident about our ability to answer difficult questions better than anyone else, it’s probable no philosophy would ever get done. And Churchland modestly goes on to admit to asking the Buddhists some dumb questions (‘What’s your equivalent of the Ten Commandments?’). Alas, I think some of her views on moral philosophy might benefit from further reflection.

Her basic proposition is that human morality is a more complex version of the co-operative and empathetic behaviour shown by various animals. There are some interesting remarks in her account, such as a passage about human scrupulosity, but she doesn’t seem to me to offer anything distinctively new in the way of a bridge between mere co-operation and actual ethics. There is, surely, a gulf between the two which needs bridging if we are to explain one in terms of the other. No doubt it’s true that some of the customs and practices of human beings may have an inherited, instinctive root; and those practices in turn may provide a relevant backdrop to moral behaviour. Not morality itself, though. It’s interesting that a monkey fobbed off with a reward of cucumber instead of a grape displays indignation, but we don’t get into morality until we ask whether the monkey was right to complain – and why.

Churchland never accepts that. She suggests that morality is a vaguely defined business; really a matter of a collection of rules and behaviours that a species or a community has cobbled together from pragmatic adaptations, whether through evolution or culture (quite a gulf there, too). She denies that there are any deep principles involved; we simply come to feel, through reinforcement learning and imitation, that the practices of our own group have a special moral quality. She groups moral philosophers into two groups; people she sees as flexible pragmatists (Aristotle, for some reason, and Hume) and rule-lovers (Kant and Jeremy Bentham). Unfortunately she treats moral rules and moral principles as the same, so advocates of moral codes like the Ten Commandments are regarded as equivalent to those who seek a fundamental grounding for morality, like Kant. Failure to observe this distinction perhaps causes her to give the seekers of principles unnecessarily short shrift. She rightly notes that there are severe problems with applying pure Utilitarianism or pure Kantianism directly to real life; but that doesn’t mean that either theory fails to capture important ethical truths. A car needs wheels as well as an engine, but that doesn’t mean the principle of internal combustion is invalid.

Another grouping which strikes me as odd is the way Churchland puts rationalists with religious believers (they must be puzzled to find themselves together) with neurobiology alone on the other side. I wouldn’t be so keen to declare myself the enemy of rational argument; but the rationalists are really the junior partners, it seems, people who hanker after the old religious certainties and deludedly suppose they can run up their own equivalents. Just as people who deny personhood sometimes seem to be motivated mainly by a desire to denounce the soul, I suspect Churchland mainly wants to reject Christian morality, with the baby of reasoned ethics getting thrown out along with the theological bathwater.

She seems to me particularly hard on Kant. She points out, quite rightly, that his principle of acting on rules you would be prepared to have made universal, requires the rules to be stated correctly; a Nazi, she suggests, could claim to be acting according to consistent rules if those rules were drawn up in a particular way. We require the moral act to be given its correct description in order for the principle to apply. Yes; but much the same is true of Aristotle’s Golden Mean, which she approves. ‘Nothing to excess’ is fine if we talk about eating or the pursuit of wealth, but it also, taken literally, means we should commit just the right amount of theft and murder; not too much, but not too little, either. Churchland is prepared to cut Aristotle the slack required to see the truth behind the defective formulation, but Kant doesn’t get the same accommodation. Nor does she address the Categorical Imperative, which is a shame because it might have revealed that Kant understands the kind of practical decision-making she makes central, even though he says there’s more to life than that.

Here’s an analogy. Churchland could have set out to debunk physics in much the way she tackles ethics. She might have noted that beavers build dams and ants create sophisticated nests that embody excellent use of physics. Our human understanding of physics, she might have said, is the same sort of collection of rules of thumb and useful tips; it’s just that we have so many more neurons, our version is more complex. Now some people claim that there are spooky abstract ‘laws’ of physics, like something handed down by God on tablets; invisible entities and forces that underlie the behaviour of material things. But if we look at each of the supposed laws we find that they break down in particular cases. Planes sail through the air, the Earth consistently fails to plummet into the Sun; so much for the ‘law’ of gravity! It’s simply that the physics practices of our own culture come to seem almost magical to us; there’s no underlying truth of physics. And worse, after centuries of experiment and argument, there’s still bitter disagreement about the answers. One prominent physicist not so long ago said his enemies were ‘not even wrong’!

No-one, of course, would be convinced by that, and we really shouldn’t be convinced by a similar case against ethical theory.

That implicit absence of moral truth is perhaps the most troubling thing about Churchland’s outlook. She suggests Kant has nothing to say to a consistent Nazi, but I’m not sure what she can come up with, either, except that her moral feelings are different. Churchland wraps up with a reference to the treatment of asylum seekers at the American border, saying that her conscientious feelings are fired up. But so what? She’s barely finished explaining why these are just feelings generated by training and imitation of her peer group. Surely we want to be able to say that mistreatment of children is really wrong?