Liberalism is characterized by paradox. It is a creed with sacred books, sacred names and a sacred history, but without a universally acceptable definition. It emerged slowly, first in England, then in France, spread with difficulty, yet is fading even more slowly—if it is indeed fading at all. From time to time its tenets have seemed to attain final expression, whether in the Declaration of Independence, the Declaration of the Rights of Man and the Citizen, or in John Stuart Mill's Liberty. Invariably these formulations have come at last to seem inadequate, and to need re-interpretation if they are to retain their reputation. Such re-interpretation has usually been forthcoming. Liberalism, to the vexation of conservatives and socialists, like a goat with exceptionally powerful digestion, finds it possible to absorb almost anything into itself, even the most trenchant criticism. Only the advocates of force for the sake of force, or of the suppression, on principle, of free thought, have been invariably rejected by the liberal consensus. Liberalism has therefore remained the creed, not of governments, but of oppositions, happiest in a critical, rather than a constructive role.