In the meantime he had been appointed Lecturer in Philosophy at University College London, where he gave courses on the history of modern philosophy, logic, and social philosophy. At the London School of Economics he lectured on sociology, ethics and the history of political ideas. During World War I the London School of Economics requested that his military service be postponed as he was standing in to give the courses which had previously been given by R.H. Tawney, Clement Attlee and Charles Mostyn Lloyd.