In the first place, even admitting the universal pressure of certain facts, it by no means follows that the theistic interpretation of those facts is the only one admissible. There is no exception to the fact that men have everywhere come to the conclusion that the earth was flat, and yet a wider and truer knowledge proved that universal belief to be quite false. The fact of a certain belief being universal only warrants the assumption that the belief itself has a cause, but it tells us nothing whatever concerning its truthfulness. The truth here is that the argument from universality dates its origin from a stage of human culture suitable to the god idea itself, a stage when very little was known concerning the workings of the mind or the laws of mental development. Otherwise it would have been seen that all the universality of a belief really proves is the universality of the human mind--and that means that, given an organism of a certain kind, it will react in substantially an identical manner to the same stimuli. Thus it is not surprising to find that as the human organism is everywhere fundamentally alike, it has everywhere come to the same conclusions in face of the same set of conditions. A man reacts to the universe in one way, and a jelly fish in another way. And universality is as true of the reactions of the latter as it is of those of the former. And this means that a delusion may be as widespread as truth, a false inference may gain as general an acceptance as a true one. What belief has been more general than the belief in witches, fairies, and the like? But we see in the prevalence of these and similar beliefs, not a presumption of their truth, but only the grounds for a search after the conditions, social and psychological, which gave them birth. The truth is that the conditions which give rise to the belief in gods are found in all ages, and no one would be more surprised than the Atheist to find it otherwise. But here, precisely as in the case of good and bad spirits, the vital question is not that people have everywhere believed in the existence of supernatural beings,[1] but an understanding of the conditions from which the beliefs themselves have grown. That alone can determine whether in studying the god idea we are studying the acquisition of a truth or the growth of a fallacy.