But, at this point, we must stop a little to define what is meant by the science of religions. Science, in this sense, has so far departed from its strict and etymological signification of knowledge, as to connote exact knowledge based upon ascertained fact, while a science is generally held to mean an organized system in which the largest possible number of related facts are gathered together with reference to one common subject of study. At first sight, it appears that nothing can be more rigidly excluded by this definition than religion, which has been defined as “the effective desire to be in right relation to the power manifesting itself in the universe[5].” This, which in some quarters would be called the religion “of the heart,” can never form the subject of study based upon exact knowledge, because the relations between any human being and the power manifesting itself in the universe can be known only, so far as we can see, to that being and to that power. But in the science under consideration, there is no question of religion generally, but of religions, which is a very different thing. By a religion, we generally mean the assembly of beliefs, traditions, and forms of worship which go to make up a faith or cult, and this, as it must, according to the experience of all history, have come into being through the agency of some man or men, should go through the same evolutionary process as all other human institutions. Hence there is at first sight a considerable probability that all religions whatever will be found on examination to follow the same law of development by the survival of those best fitted to their environment that we have seen operative in the case of animal forms. Here, however, the Christian—or for that matter, the adherent of any faith which claims to have been founded by a special revelation—finds himself in the presence of a dilemma. His own faith, whether it be Christianity or another, is in his eyes true, as being not the work of man, but of God, and all others are false. How therefore are they to be compared? Is the Jew, who believes the Law to have been delivered to his people “among the thunders of Sinai,” the Parsi who is taught the special inspiration of Zoroaster by the “Omniscient Lord” Ahura Mazda, or the Mohammedan who thinks that Mohammed received the Koran from Allah himself, to be told that his faith has developed according to the same laws as that of the Christian, who is convinced that his has no other source than the teaching of the Divine Founder of Christianity?