The use of any science lies in its application to practical purposes. For Christianity, the use of the science of religion consists in applying it to show that Christianity is the highest manifestation of the religious spirit. To make this use of the science of religion, we must fully and frankly accept the facts it furnishes, and must recognise that others are at liberty to use them for any opposite purpose. But we must also insist that the science of religion is limited to the establishment of facts and is excluded from passing judgment on the religious value of those facts. The science of religion as a historical science is concerned with the chronological order, and not with the religious value, of its facts; and the order of those facts does not determine their value any more in the case of religion than in the case of literature or art. But if their value is a question on which the science refuses to enter, it does not follow that the question is one which does not admit of a truthful answer: science has no monopoly of truth. The value of anything always implies a reference to the future: to be of value a thing must be of use for some purpose, and what is purposed is in the future. Things have value, or have not, according as they are useful or not for our purposes. The conviction that we can attain our purposes and ideals, the conviction without which we should not even attempt to attain them is faith; and it is in faith and by faith that the man of religion proposes to conquer the world. It is by faith in Christianity that the missionary undertakes to convert men to Christianity. The comparative value of different religions can only be ascertained by comparison of those religions; and the missionary, of all men, ought to know what is to be learnt from such comparison. It is sometimes supposed (wrongly) that to admit that all religions are comparable is to admit that all are identical; but, in truth, it is only because they differ that it is possible to compare them.