Michael Potter is Professor of Logic in the Faculty of Philosophy at the University of Cambridge, and has been a Fellow of Fitzwilliam College since 1989. His forthcoming book, Wittgenstein1916, will be a study of Wittgenstein's views on ethics and religion during the First World War, during the time he was writing his famous Tractatus.

We spoke to him about Wittgenstein, the linguistic turn and the importance of logic to the study of language.

Can you start by explaining what we mean when we talk about the linguistic turn in philosophy?

It is usually attributed to Gottlob Frege in his 1884 book, The Foundations of Arithmetic. He was interested in explaining arithmetic and his account was based on the idea of trying to explain what sentences like "2+2=4" mean. He was worried that merely explaining what a whole sentence means would leave the question answered, but not the question of what really are the numbers?

So he adopted what's called the "context principle". This turned what looks like a metaphysical question, "what is a natural number?" or "what is the number 2?", into a linguistic question about how the word "two" functions in arithmetical questions. So, he adopted this approach for a very specific purpose in the philosophy of arithmetic, but the idea became important in 20th century philosophy. What Frege taught was that when you're confronted with a philosophical question, don't just dive into the question cold. Start by trying to analyse the way that the language is used in the formulation of the question. So, I think that's what the linguistic turn has been taken to mean.