The world, according to Ted Sider, has a basic structure. An optimal description of the world must capture this structure. It must also consist of truths. But these are two distinct requirements. We can produce more and more truths about the world and still not come any closer to capturing its structure. To do the latter we need to produce not just truths, but truths of the right sort. Now it has long been acknowledged that a mere assemblage of truths does not count for much. They might be uninteresting and insignificant truths; for that matter, they might be interesting and significant truths, but assembled in an uninteresting and insignificant way – without any attempt at systematisation or explanation, without any attempt to establish connections. The idea of basic structure gives a further fillip to this familiar fact. It signals another respect in which, if we are to give the best possible account of the world, we need to do more than tell the truth. The concepts we use to couch the truth – the properties to which we advert, the sorts of thing we recognise as instantiating these properties, even the connectives we use to conjoin claims about such things – need to reflect the world’s basic structure. They need to ‘carve at the joints’. There is a privileged way to write the book of the world.

LRB 30 August 2012 | PDF Download