 After Morley read Hirst's contributions to Cassell's biography of Gladstone edited by Sir Wemyss Reid, he asked Hirst to spend a few weeks with him at Hawarden Castle (Gladstone's home) to help him write Gladstone's authorised biography.Hirst opposed the Boer War and was a co-founder of the League Against Aggression and Militarism.After he had left Oxford, Hirst edited political and economic books for Harper's, including one on Toryism by F. E. Smith and one on Socialism by R. C. K. Ensor.