How does the animated meat inside our heads produce the rich life of the mind? Why is it that when we reflect or meditate we have all manner of sensations and thoughts but never feel neurons firing? It's called the "hard problem", and it's a problem the physician, philosopher and author Raymond Tallis believes we have lost sight of – with potentially disastrous results.

In his new book, Aping Mankind – about which he was talking this week at the British Academy – he describes the cultural disease that afflicts us when we assume that we are nothing but a bunch of neurons.

Neuromania arises from the doctrine that consciousness is the same as brain activity or, to be slightly more sophisticated, that consciousness is just the way that we experience brain activity.

If you think the brain is a machine then you are committed to saying that composing a sublime poem is as involuntary an activity as having an epileptic fit. You will issue press releases announcing "the discovery of love" or "the seat of creativity", stapled to images of the brain with blobs helpfully highlighted in red or blue, that journalists reproduce like medieval acolytes parroting the missives of popes. You will start to assume that the humanities are really branches of biology in an immature form.

What is astonishing about this rampant reductionism is that it is based on a conceptual muddle that is readily unpicked. Sure, you need a brain to be alive, but to be human is not to be a brain. Think of it this way: you need legs to walk, but you'd never say that your legs are walking.

The same conflation can be exposed in a more complex way by reflecting on the phenomenon of perception. It is what we do every moment of the waking day. You're doing it right now: casting an eye to the paper in front of you and seeing words on a page. But if you were just a brain, you would not see words. There'd be just the gentle buzz of neuronal activity in the intracranial darkness.

The distinguished evolutionary psychologist Robin Dunbar acted as interlocutor to Tallis at the British Academy event. He didn't want to pick a fight, though he was clearly not going along with the attack. Surely this is just the way science works, he asked? We begin with simple levels of explanation and then proceed to more complex ones, working from the bottom up. Well, responded Tallis with his customary quick wit: "If you go bottom up, it's important to go up the right bottom."

Tallis did not think that better scanners and more sophisticated analysis would solve the problem either. Even if neuroscience one day tracks every single neuron firing in real time, you won't be watching consciousness. You'll have more precise correlations to play with, yes. But people will still experience pain and say "Ouch!", not "Oh, no worries: it's just neuron cluster 148 lighting up."

So why can't consciousness be thought of as just the way we experience brain activity, Dunbar continued? Because that's dishonest, Tallis retorted. Inside that innocent-sounding sentence, you have smuggled those two little words "we experience". And that's the entire problem: how do we experience?

Tallis doesn't claim to know. He described himself as an "ontological agnostic", the nature of consciousness being a tremendous mystery. "We just don't know how we should think about being and how mind fits into nature. But we'll never learn if we start out taking all the wrong paths."