Neuroscience is not known for underselling its genius to solve that problem called human nature. There's neuro-economics, neuro-theology, neuro-interior-design for all I know.

Here's a new one to me: 'biological justice'. The idea is that brain scanners in law courts will be able to tell not only if a suspect is telling the truth, but will be able to read, direct from the neurons, whether mens rea applies: juries will be a thing of the past as guilt will be determined by printout.

The optimism of the new science is such that caution goes to the wind, and that really matters when it comes to issues like justice. Michael Gazzaniga, the leading researcher on whether brain scan evidence should be admitted in US courts, admitted in a seminar I attended that it'd be another 25 years before the science is ready - which is code for 'don't hold your breath'. Though the time gap is convenient because it allows neuroscience to continue to write its promissory notes. So how to tell whether they're worth the paper they're written on?

As a concerned non-specialist, I've four rules of veracity that I tend to apply.

1. It's not brains or neurons that are conscious or have culture, but persons. Any account that has a fixation on what's going on inside the skull is sure to be inadequate and wrong. Listen to this conversation between a professor of neuro-aesthetics and two artist practitioners and ask yourself whether anything the good professor suggests remains standing by the end of it.

That said, this does not mean that neuroscience has nothing to contribute to discussions about culture. To my mind, Iain McGilchrist shows it does. And that's because he allows culture to be the ultimate arbiter of culture, not neuroscience, which means he avoids reductionism and neuro-literalism.

2. Be wary of biological explanations of consciousness of the form, 'evolution can explain everything' - the peacock's tail explanation of Shakespeare's sonnets etc. It's far from clear that the link between biology and consciousness is any stronger or necessary than the link between breeze blocks and architecture. Ray Tallis is good on this. Watch out for his next book.

3. Beware obfuscatory language that passes itself off as an explanation. Appealing to feedback loops is a favourite strategy, though my pocket calculator is packed with them and it has nothing to say about Mozart, so far as I know.

A related trick is neologisms: I was reading about 'sentition' and 'ipsundrum' recently. They're like black boxes into which the purported explanation disappears.

4. Ask yourself what the author is arguing against. It's probably only the inadequacies of their own discipline. For example, Antonio Damasio has surely rightly pointed out that emotions are involved in decision-making as much as rationality but that does not mean he's cracked the hard problem. Only that the materialist philosophy that underpins much contemporary biology has been blind to what individuals as long ago as Plato took for granted, and individuals as recently as Freud reminded us of.