unreasonable only in case he did not exist. If, for instance, you were to condemn a religion of human or animal sacrifices by virtue of your subjective sentiments, and if all the while a deity were really there demanding such sacrifices, you would be making a theoretical mistake by tacitly assuming that the deity must be non-existent; you would be setting up a theology of your own as much as if you were a scholastic philosopher.
To this extent, to the extent of disbelieving peremptorily in certain types of deity, I frankly confess that we must be theologians. If disbeliefs can be said to constitute a theology, then the prejudices, instincts, and common sense which I chose as our guides make theological partisans of us whenever they make certain beliefs abhorrent.
But such common-sense prejudices and instincts are themselves the fruit of an empirical evolution. Nothing is more striking than the secular alteration that goes on in the moral and religious tone of men, as their insight into nature and their social arrangements progressively develop. After an interval of a few generations the mental climate proves unfavorable to notions of the deity which at an earlier date were perfectly satisfactory: the older gods have fallen below the common secular level, and can no longer be believed in. To-day a deity who should require bleeding sacrifices to placate him would be too sanguinary to be taken seriously. Even if powerful historical credentials were put forward in his favor, we would not look at them. Once, on the contrary, his cruel appetites were of themselves credentials. They positively recommended him to men's imaginations in ages when such coarse signs of power were respected and no others could be understood. Such deities then were worshiped because such fruits were relished.
