The great mistake which he commits is obvious, and the cause hardly less so. The mistake is twofold: first, he attributes to the earliest period of Christianity that which was only true of a later; and secondly, he confounds the circumstances of the spread of Christianity with the cause which gave it force.(624) The powerful influence of the causes which he specifies cannot be doubted;(625) and we may hold it to be not derogatory to our religion that it admits of union with every class of efficient causes; and adapts itself so fully to man’s wants, as to accept the support of ordinary sources of influence. But the causes which he alleges operated far less strongly, and some of them not at all, in the primitive age of Christianity. The discussion of this period lay beyond Gibbon’s purpose; and as he dwelt wholly on the aspects of a later age, he has left the impression that the earliest age partook of the same characteristics. Nor is he correct in regarding the five causes as solely efficient. There is a subtler force at work, of the operation of which they exhibit only the conditions. They reveal the mechanism, but do not explain the principle. Without judging him as a theologian in omitting the theological cause for an alleged supernatural power, he must be censured as a historian in failing to appreciate the spiritual movement at work in Christianity, the deep excitement of the spiritual faculty, the yearning of the mind after truth and holiness. The same fault is observable in his appreciation of religion generally, and not merely of Christianity. With the want of spiritual perception common to his age, he had not the ethical sensibility to appreciate the internal part of a religious system; and hence he regards unworldly phenomena in the tone of the political world of his time.