Vincent Deary is a therapist, and this book is the first part of a trilogy. How We Are is about human nature. Books two and three will be called How We Break and How We Mend. Three serious tomes, backed by a serious publisher. You open it thinking: this is not going to be an easy self-help book where everything is mapped out for you. It won’t be a walk in the park.

In fact, pretty much the first thing Deary does is to examine the concept of walking in a park. ‘“A walk in the park” is a synonym for ease,’ he tells us, ‘because the park knows how to walk.’ In other words, when you enter a park, you don’t have to make any decisions, because the park has already made them for you. The paths are marked out. All you have to do is follow them. You don’t have to think — or at least, you don’t have to think any more than you want to. ‘A good park anticipates our desire,’ says Deary. ‘Anticipated desire is the key to leisure.’

Strolling down the path of this leisurely thought, Deary then asks us to look away from the path. Human beings, he suggests, are themselves like parks. Driven by our desires, the evolutionary process has made us into a living concoction of beaten paths. ‘You are the record, the embodiment of life’s ceaseless desiring, written in tiny molecular hand, transcribed and translated into flesh, from dust and water.’

Wow! Peering down this conceptual mineshaft, we now get an idea of Deary’s project. He wants us to think — about life, the universe, the bits and pieces we are made from.‘Where do we start?’, he asks. Well, a long time ago, we were nothing but dust and water, and then, after a billion years, ‘a couple of buckets of water and a bag of earth became this you, here now, so blithely reading, turning pages.’ How did this happen? How did dust become human? Because, says Deary, the dust was hungry. As he puts it: ‘Imagine the first attempts at hunger, matter desperately maintaining its structure through stealing other matter.’ First the structure is maintained. Then it becomes more complex. Finally it becomes us.

This is a book that gets your mind whizzing off in lots of directions. Having made us contemplate the primordial ooze, Deary cuts to the two world wars of the last century, and gets us to see how, for some soldiers, killing became second nature. Not quite a walk in the park, but you can be trained to perform combat duties ‘on automatic’. Then Deary gets us to think how much of our lives are performed automatically. It’s a lot. We drive automatically. We shop automatically. In fact, if we were to stop doing all the normal stuff automatically we’d become self-conscious — think of how it feels when you’re walking along in the knowledge you’re being observed. Yes, slightly weird.

So what’s going on? Our brains are like complex machines that make us move around on automatic. Mostly, the conscious centres of our minds are bypassed. And memory, of course, is not an archive — it’s more like a servant, updating itself in the way that feels most helpful, like a corrupt news agency. And even when we think we’re making a conscious decision, we’re not; the decision is made before we know it, in the murk of our unconscious. What we believe to be the moment of agency is actually more like the moment of acknowledgment. In other words, I may think I’m the boss of my thoughts and actions, but really I’m the boss’s PR man.

Towards the end, Deary says, ‘Sara, a friend in publishing, tells me I’ll have to find my trait unaire, my USP, my unique selling point.’ So, what exactly is this? It’s a book about human nature. It’s crammed with ideas. It makes your head spin, in a good way. It tells us that human beings form habits, and that we are less in control of our minds than we thought we were. This is how we are. I’m looking forward to how we break.