He was a bibliophile who amassed a considerable collection of books relating to the Enlightenment, much of which is now in the John Rylands Library in Manchester. He also bequeathed a collection of c.1,000 volumes concerning Charles de Secondat, Baron de Montesquieu (1689-1755) to the Bodleian Library. He is the author of ''Montesquieu: A Critical Biography'' (Oxford University Press, 1961), a standard introduction to Montesquieu's life and thought as well as to the historical and intellectual background.