Moreover, institutions are never an adequate expression of the ideal. "Men are never as good as the goodness they know. Institutions reveal the same truth. The margin between what society knows and what it is" makes radicalism possible. In his introduction to The Revolt of Islam, Shelley expresses the same thought: "The French Revolution may be considered as one of those manifestations of a general state of feeling among civilized mankind produced by a defect of correspondence between the knowledge existing in society and the improvement or gradual abolition of political institutions." The greater that this defect of correspondence becomes, the more intense will be the radicalism that inevitably ensues. Radicals want a change. The extent of this change differentiates them fairly well among themselves.

Some would completely sweep away every existing institution. Thus Shelley thought the great victory would be won if he could exterminate kings and priests at a blow. Let the axe strike at the root, the poison-tree will fall.