From time to time, not very often, it looks as though the world has given philosophy a job to do. Now is such a moment. At last, a big abstract noun – truth – is at the heart of a cultural crisis and philosophers can be called in to sort it out.
Send them back. Philosophers’ problems with truth are not the same as the world’s. The post-truth debate cannot be readily fixed by a better theory. Most of the time, people are clear enough what makes something true. To use Alfred Tarski’s famous example from the 1930s, “Snow is white” is true if and only if snow is white. If that sounds obvious, that’s the point. A statement is true if and only if it corresponds to a state of affairs or event that obtains in the world.