If big ideas come in small packages, this book confirms that aphorism. It is a book about ideas and philosophy but one underpinned by scholarship and extensive reading. When I saw John Gray at the Edinburgh Book Festival, he quoted a writer who had wondered why people praised him, when the people they should really be praising are the writers he had read – the writer as product of reading.

A key theme of the book is gnosticism, the ancient belief that the world is created by a demiurge, as sort of artisanal god but not the supreme being. A sort of assistant god, but one that creates evil as well as good. Gray suggests that the currently widespread belief in the power of knowledge to resolve life’s mysteries is a descendant of gnosticism.

It is a very stimulating read, from a brilliant thinker who can also write beautifully. And it is short, for a philosophy book – what more do you want?