Inevitably the discipline has spawned the new science — or parascience — of neuroaesthetics. Art will yield its mysteries as every aspect of creation and perception is explained by activity in different areas of the brain, with no artistic consciousness or self-awareness involved, since the brain subsumes both. On the means by which beauty is perceived doubts have long existed, though not for Professor Semir Zeki of University College, London: "The artist in a sense is a neuroscientist, exploring the potential and capacities of the brain, though with different tools. How such creations can arouse aesthetic experiences can only be fully understood in neural terms. Such an understanding is now well within our reach." 

Like Tallis, Marilynne Robinson warns against the reductionism all this can involve, the "stripping away" of culture and consciousness and the "crusade" to debunk religion. For me the word "stripping" has a particular resonance. For many years my wife has restored Old Masters, often struggling to repair damage wreaked by past scientistic theories of restoration, when "objectivity" was all, subjectivity a dirty word, and the past something to be adjusted to meet the demands of the present. Again the effect was simplifying and reductive (removal of complex glazes, flattening of perspective, louder colours, synthetic varnishes). God knows what new injuries restorers bursting with neuroaesthetic conceits could inflict on a Renaissance canvas. 

Ironically, a few decades ago it was the postmodernist fashion, laid down by Michel Foucault, Richard Rorty and others, to question the truth of science itself. Now neuroscience is said, sometimes by the same folk, to reveal the raw facts about humanity and its works. In literary criticism, forget the jargon of semiotics and prepare yourself to discover how axons and neurons help in the reading of a text. 

It is not the first time scientific concepts or discoveries have influenced literature. A century or so ago many writers were fascinated by the idea of entropy (the second law of thermodynamics) as a metaphor for the dissolution of energy and subsequent chaos. Mirror neurons, currently fashionable in the arts community, carry a perkier, optimistic message. The excitement comes from the notion that because mirror neurons are activated by seeing someone doing something and doing it ourselves, human empathy is built into the brain. "It is ethics made easy,"  says Tallis. That mirror neurons were first located in monkeys and have yet to be conclusively shown to work in humans, and that a mirror is not conscious of the image it hosts, have done nothing to still the excitement.