Under its influence they make all the progress compatible with the creed, and finally outgrow it; when a period follows of criticism and negation, in which mankind lose their old convictions without acquiring any new ones, of a general or authoritative character, except the conviction that the old are false.

The period of Greek and Roman polytheism, so long as really believed in by instructed Greeks and Romans, was an organic period, succeeded by the critical or sceptical period of the Greek philosophers.

Another organic period came in with Christianity.

The corresponding critical period began with the Reformation, has lasted ever since, still lasts, and cannot altogether cease until a new organic period has been inaugurated by the triumph of a yet more advanced creed.

These ideas, I knew, were not peculiar to the St.Simonians; on the contrary, they were the general property of Europe, or at least of Germany and France, but they had never, to my knowledge, been so completely systematized as by these writers, nor the distinguishing characteristics of a critical period so powerfully set forth; for I was not then acquainted with Fichte's _Lectures on the Characteristics of the Present Age_.