Political liberty has a second effect, one, perhaps, still more important: it forces all questions to submit to the test of practical experiment. As long as the liberty is only in the thought, it is vain and intemperate; everything seems permitted, and everything possible to those who are not responsible for the effects of an act: man's thought, intoxicated with itself, runs riot in the vagueness of infinite space and time. But when to liberty of thought is superadded political liberty,--when, instead of treating questions speculatively, they have to be virtually solved,--when men are charged as real actors to transform into facts their own opinions or those of the spectators who are looking on,--then it is that the human mind, making its own strength the object of its reflection and examination, is driven to the admission that it does not dispose at its own will of the world, and that even in order to satisfy itself, it must confine itself to the limits imposed by good sense, by justice, and by possibility,--then it is that it learns to govern itself, and to hold itself responsible for its acts. Responsibility engenders discretion, but is itself engendered by liberty alone. {xlii} Our own times have furnished us with three great examples of the salutary empire exercised by political liberty in furnishing an escape from the embarrassment of situations, and in solving questions the most different--I might say the most contrary--in their nature. We have only to cast our eyes over the contemporary histories of England, of the United States of America, and of France herself, to discover their examples and their authority as precedents.