This process of development has been well delineated by a living French writer, in his Lectures on European civilization, who shall be quoted at some length. "If we reduce religion," he says, "to a purely religious sentiment . . . it appears evident that it must and ought to remain a purely personal concern. But I am either strangely mistaken, or this religious sentiment is not the complete expression of the religious nature of man. Religion is, I believe, very different from this, and much more extended. There are problems in human nature, in human destinies, which cannot be solved in this life, which depend on an order of things unconnected with the visible world, but which unceasingly agitate the human mind with a desire to comprehend them. The solution of these problems is the origin of all religion; her primary object is to discover the creeds and doctrines which contain, or are supposed to contain it. "Another cause also impels mankind to embrace religion . . . From whence do morals originate? whither do they lead? is this self-existing obligation to do good, an isolated fact, without an author, without an end? does it not conceal, or rather does it not reveal to man, an origin, a destiny, beyond this world? The science of morals, by these spontaneous and inevitable questions, conducts man to the threshold of religion, and displays to him a sphere from whence he has not derived it. Thus the certain and never-failing sources of religion are, on the one hand, the problems of our nature; on the other, the necessity of seeking for morals a sanction, an origin, and an aim. It therefore assumes many other forms beside that of a pure sentiment; it appears a union of doctrines, of precepts, of promises. This is what truly constitutes religion; this is its fundamental character; it is not merely a form of sensibility, an impulse of the imagination, a variety of poetry.