Churchland is a proud Humean who believes in obeying your natural sympathies and checking them as you go against the imagined perspective of an impartial observer. She favors this approach over the available alternatives on the grounds of evidence, pragmatism, and even, implicitly, ethic...Still, as a basis for doing philosophy per se, it has some obvious difficulties. You can accept that there’s a biological substrate to any given aspect of the human condition without assuming that more information about the brain will meaningfully deepen your understanding ... it seems uncontroversial to suggest that you can glean more about what it means to live and think by reading Ulysses than you ever could by shoving James Joyce inside an MRI machine ... The test of a moral philosophy is surely not where it begins so much as where it leads, and here the results are mixed. As Churchland admits, a system based on the glow of social approbation and affection versus the shame and pain of their inverse is vulnerable to all kinds of abuse. ... The severest dangers of essentializing in this way are obvious. Yet there are also other, subtler risks.
True, as Ms. Churchland would say, even though we know a Monet painting is made up of chemicals, that knowledge doesn’t stop us from valuing its artistry. But we don’t, at the same time, view the pleasure we get from such artistry as a mistaken theory, a mere folk explanation for the work that chemicals do. Nor do we root the Monet’s value—say, its emotional power—in the way it generates oxytocin ... Ms. Churchland’s previous books have advanced a potent philosophy of the human mind. But it falls short in explaining the cherished human values we choose to designate as moral.
... [a] strikingly unphilosophical philosophy book ... To make her case [Churchland] devotes three-quarters of her book to scientific findings connecting brain functions to moral behavior. However, she pays considerably less attention to the ethical theory needed to support her argument and, in the end, doesn’t convince that neurophilosophy should supersede moral philosophy. There are fascinating nuggets in the research Churchland cites, particularly regarding early brain developments that shaped our moral leanings ... Her examples are varied and provocative, but fall short of a unified theory of how the brain motivates morality. She recites the findings ... While comprehensive in scope, Churchland’s book is consistently dry, and the lack of connections between chapters makes for a stilted read. A larger problem, though, is that the science doesn’t support her philosophical theory—presented in the slim final quarter of the book—that neuroscience should replace traditional ethics ... Scholars in either field are unlikely to feel crushed ... Churchland’s engagement with neuroscience makes her an unusual figure in philosophy, and her endeavor is certainly worthwhile. It would be more impressive, though, were she less eager to reject philosophical methods in her embrace of neuroscience. Our moral intuitions may well be grounded in biology, but Churchland fails to explore the most pressing questions of when, or even if, we should rely on such intuitions as a guide.