The aim of all true philosophy is to attain to the insight of First Principles, yea, to the insight of the Absolute First Principle from which whatever now _is_ must be derived, and in which whatever _is_ must have its intelligible ground and sufficient reason. There exists in man, as the essential characteristic of his humanity, a power or faculty of intelligence, best named the _Reason_, which awakens in him the desire and furnishes to him the law that enables him to fulfill the inherent desire of combining all his manifold knowledges in the unity of such _Absolute First Principle_; and the one fundamental law of this faculty is the _Law of Sufficient Reason_, which has been thus enounced by Leibnitz: "Whatever exists, or begins to be, must have a sufficient reason for its existence, and why it is as it is, and not otherwise;" or, to give the principle a fuller, and at the same time a legitimate expansion--For all genesis, or beginning, there must be an adequate _Cause_; beneath all appearance, all changeful and fleeting phenomena, there must be a permanent _Being_ or _Reality_; beyond all the diverse and manifold, there must be an ultimate _Identity_, an incomposite indivisible _Unity_; and in all order and special adaptation, there must be a unifying _Thought_, a definite _Purpose_ and _End_. The Reason of man can find satisfaction and harmony only in the recognition of an Absolute First Principle which shall comprehend and unite all these universal and necessary ideas which are the correlates of the facts of experience; that is, an Absolute First Principle which shall be the Ultimate Reality, the Ultimate Cause, the Ultimate Unity, and the Ultimate Reason of all existence. In other words, the Reason is not and can not be satisfied without "the clear insight of a _Causative Principle_ containing, predetermining, and producing all the actual results we see around us, with their orderly relations in reference to a final purpose, reason, or end; and which causative principle exists not only as the originative and constructive, but also as the conservative energy of all things;" a Being who "is before all things, and by whom all things consist," "from whom, in whom, and to whom are all things." And now what is this Absolute First Principle, causative of all existence, which the spontaneous reason has always intuitively apprehended, and which the reflective reason has always found to be the adequate, and only adequate explanation of the universe? I answer in a word, it is AN UNCONDITIONED WILL OR SELF-DIRECTIVE POWER, SEEING ITS OWN WAY, AND HAVING THE REASON AND LAW OF ITS ACTION IN ITSELF ALONE. This always and every where has been intuitively apprehended, with more or less clearness, as standing at the fountain-head of all existence. This, then, we shall postulate as the fundamental axiom of all rational integration, viz., AN UNCONDITIONED WILL, _the principle of all Reality, all Efficiency, and all Perfection_.