The two principles referred to are Authority and Liberty, and the names of the two schools of Socialistic thought which fully and unreservedly represent one or the other of them are, respectively, State Socialism and Anarchism. Whoso knows what these two schools want and how they propose to get it understands the Socialistic movement. For, just as it has been said that there is no half-way house between Rome and Reason, so it may be said that there is no half-way house between State Socialism and Anarchism.

¶ 4 - State Socialism and Anarchism: How Far They Agree, and Wherin They Differ (1888)