(Attempts to show that in the field to which reason applies we are compelled to use it, and are justified in trusting it.) The great majority of people are brought up to believe that some particular set of dogmas are objects of faith, and that there are penalties more or less severe for the application of reason to these dogmas. What particular set it happens to be is a matter of geography; in a crowded modern city like New York, it is a matter of the particular block on which the child is born. A child born on Hester Street will be taught that his welfare depends upon his never eating meat and butter from the same dish. A child born on Tenth Avenue will be taught that it is a matter of his not eating meat on Fridays. A child born on Madison Avenue will be taught that it is a question of the precise metaphysical process by which bread is changed into human body and wine into human blood. Each of these children will be assured that his human reason is fallible, that it is extremely dangerous to apply it to this "sacred" subject, and that the proper thing to do is to accept the authority of some ancient tradition, or some institution, or some official, or some book for which a special sanction is claimed. Has there ever been in the world any revelation, outside of or above human reason? Could there ever be such a thing? In order to test this possibility, select for yourself the most convincing way by which a special revelation could be handed down to mankind. Take any of the ancient orthodox ways, the finding of graven tablets on a mountain-top, or a voice speaking from a burning bush, or an angel appearing before a great concourse of people and handing out a written scroll. Suppose that were to happen, let us say, at the next Yale-Harvard football game; suppose the news were to be flashed to the ends of the earth that God had thus presented to mankind an entirely new religion. What would be the process by which the people of London or Calcutta would decide upon that revelation? First, they would have to consider the question whether it was an American newspaper fake--by no means an easy question. Second, they would have to consider the chances of its being an optical delusion. Then, assuming they accepted the sworn testimony of ten thousand mature and competent witnesses, they would have to consider the possibility of someone having invented a new kind of invisible aeroplane. Assuming they were convinced that it was really a supernatural being, they would next have to decide the chances of its being a visitor from Mars, or from the fourth dimension of space, or from the devil. In considering all this, they would necessarily have to examine the alleged revelation. What was the literary quality of it? What was the moral quality of it? What would be the effect upon mankind if the alleged revelation were to be universally adopted and applied?