The enemy of knowledge, as Huxley saw it, was faith: “The man of science has learned to believe in justification, not by faith, but by verification.” Huxley's language shapes itself paradoxically, as the negative form of the language of religion; that is, in its often witty and bitter rejection of religion as a method of knowing, it retains the religious structure and the sanction of feeling that goes with it. The fondest “convictions of barbarous and semi-barbarous people” are the convictions Huxley associates with religion: “that authority is the soundest basis of belief; that merit attaches to a readiness to believe; that the doubting disposition is a bad one, and scepticism a sin.” Huxley assumes “the exact reverse … to be true”. The “semi-barbarous” sounds like the John Henry Newman of the Apologia pro vita sua, published two years before.

“The improver of natural knowledge” Huxley affirms, “absolutely refuses to acknowledge authority, as such. For him, scepticism is the highest of duties; blind faith the one unpardonable sin” (p. 40). The reversal is “exact,” the refusal “absolute,” and faith, in the deliberate paradox, becomes an “unpardonable sin.” Huxley's language deliberately depends upon the mode it is rejecting. Such reversals provide the form of that “naturalizing” of religion of which James Moore has written so incisively and critically.