I was wrong about this one for about four years.

I owe this one an apology, so here it is up front rather than tucked away at the close where it would look like grace.

For years I refused to read it because I'd read its children. Every airport paperback about nudging and irrationality and the surprising truth of whatever cites this on page two, and most of them are dreadful: a study, an anecdote, a bar chart, a chapter break. I assumed the parent was the same object with a longer bibliography. That was lazy of me and I said so out loud more than once.

It isn't the same object at all. What the imitators strip out is the hedging — and the hedging is the substance. There's a moment fairly early on where he explains that the two-systems framing is a fiction, a convenient way of talking, not two little men in your skull, and that he'll go on using it because the alternative is unreadable. None of the followers ever say that. Most of them plainly believe in the little men.

The anchoring chapter is what I'd give a sceptic. It isn't clever; it's patient. Here's the effect, here's how large it is, here's what happens when we warn people it's coming, and here's the depressing news that warning them barely helps at all. I read it on a ferry and irritated my partner by narrating.

Now the case against, because eight is not ten. It's badly organised. Sections that belong together sit chapters apart, and there's a stretch in the middle where the prose stops being written and starts being assembled. The final part, on the experiencing self and the remembering self, is the weakest part of the whole book and also the bit that gets quoted most, which I'm starting to think is a general law of non-fiction.

There's also the priming material. A good deal of the social priming work he presents with confidence has not replicated, and he knew it before he died and said so publicly, plainly, with none of the wriggling you'd expect from a man defending a bestseller. That's a black mark against the chapter and a point in favour of the author, and you don't get to hold one without the other.

The objection I'd make to my own review: is a book allowed to be graded on what its imitators did to it? Deborah says obviously not, and that four years of refusing to open it was a snobbery about genre dressed up as a judgement about content. She's completely right, which is annoying, and she's also the one who left her copy at my house so I'd run out of excuses.

Eight. Read the first two parts properly, skim the third, and don't believe anyone who summarises it for you in a meeting.