"The preservation of a free system is so difficult precisely because it requires a constant rejection of measures which appear to be required to secure particular results, on no stronger grounds than that they conflict with a general rule, and frequently without our knowing what will be the costs of not observing the rule in the particular instance. A successful defence of freedom must therefore be dogmatic and make no concessions to expediency, even where it is not possible to show that, besides the known beneficial effects, some particular harmful result would also follow from its infringement. Freedom will prevail only if it is accepted as a general principle whose application to particular instances requires no justification. It is thus a misunderstanding to blame classical liberalism for having been too doctrinaire. Its defect was not that it adhered too stubbornly to principles, but rather that it lacked principles sufficiently definite to provide clear guidance, and that it often appeared simply to accept the traditional functions of government and to oppose all new ones. Consistency is possible only if definite principles are accepted. But the concept of liberty with which the liberals of the nineteenth century operated was in many respects so vague that it did not provide clear guidance."