  Prior worked intensely, often all through the night. 1949 saw the publication of his first book, a slim but potent volume titled Logic and the Basis of Ethics. It was published by the Clarendon Press and soon became prominent in Oxford. Austin liked it and Ryle approved of ‘Prior’s complete lack of mugwumpery’. In the Introduction Prior explained that by the ‘logic of ethics’ he meant ‘not a special kind of logic, nor a special branch of logic, but an application of it’, and the book is a vigorous examination of the arguments of each side in the naturalism/anti-naturalism debate.