In obedience to this demand of reason, or impelled by an innate "wonder"--"the feeling of the philosopher"--men have in all ages attempted an ideal construction and rational interpretation of the universe.[11] The Mythologies, Cosmogonies, Philosophies, Religions of the ancient world were the simple products of this innate tendency. Beyond the circle of thought illuminated by Divine revelation, the first movement of reflection was unmethodical and incomplete. Pursuing the inquiries objectively, that is, in the realm of outward nature, and not subjectively in the realm of reason, the human mind was perpetually entangled with dualistic conceptions. There were contrarieties, polarities, antagonisms, which the logical understanding could not cancel. Hence we have, as an early, perhaps the earliest, form of construction, an Oriental Dualism--as in the Adonis and Moloch of the Phœnicians, the Isis and Osiris of the Egyptians, the Ormuzd and Ahriman of the Persians, the Chaos and Love of Orpheus, the Plenum and Vacuum (Matter and Space) of Democritus, and even some lingering taint in the God and Necessity of Plato's "Timæus." But all this was unsatisfactory to human reason, which is a _unity_, and which makes its imperious demand that _absolute unity_ shall stand at the fountain-head of being. It has never been able to rest in an Ultimate which was not an Absolute--that is, a _unity_ which by its very idea and conception is the negation of all plurality and mutability; a _unity_ which is unconditioned, and yet which conditions all; an "eternal constancy," the voluntary cause of all genesis and all change.[12] It is a law of reason, under which alone it can maintain its integrity, that the _First Cause must be_ ONE, _and not many_. An absolute cause must be one in order to be absolute; two absolutes is a contradiction. With more or less clearness, men in all ages have apprehended that "the _First Principle must be one or nothing_." This is tacitly conceded in all modern systems of thought. Büchner, the materialist; Spencer, the dynamist; Hegel, the idealist; Cousin and Coleridge, the spiritualists, know no divergence here. Atheism, Pantheism, and Theism alike commence with unity at the fountain-head of being--a unity which is incomposite, absolutely continuous, every where present and eternal. Every system of philosophy is essentially an effort to show how the universe that now is has been originated by, or evolved out of, or has emanated from, a First Principle, an absolute Unity. To determine whether this absolute First Principle can be known, and, if known, how conceived and expressed aright, is the ultimate problem of all philosophy and all religion. All the answers which have been given, and, indeed, all which can be conceived, are contained in the following four propositions: