We might here at once, and with justice, enter our caveat against the attempt to invalidate a primitive datum of consciousness by alleged deductions from the exterior phenomena of human life and history. A primitive datum of consciousness is unquestionable and infallible. A process of induction is liable to the interpolations of error. The latter is therefore a lesser authority than the former, and a merely derivative assurance can not be argued against an ultimate fact. We must regard it as a philosophic canon that an experience cognition can not conflict with an intuitive belief. The exterior phenomena of life and history, properly interpreted, must harmonize with the interior facts and laws of the human mind, for what is _history_ but the development, under the conditions and relations of time, of the primitive powers, ideas, and laws of humanity? If, then, consciousness attests the presence in man's spiritual nature of a power, in the same circumstances, to choose either of several ways, we may confidently expect that the phenomena of the moral world will not belie that testimony. Now it is a palpable fact that an unbroken law of continuity and uniformity pervades the material universe. It is locked up in an unchangeable status. There is no deviation and no progression. All things remain as they were since the beginning. The fundamental fact lying at the basis of this undeviating uniformity of nature is that material causes are unipotent, and shut up to one solely possible mode of effectuation.[538] And it is equally palpable that the phenomena of the moral world, the sphere of human life and history, reveal contingency, diversity, alteriety, and progression. Humanity has not revolved in cycles, neither has it run in the inflexible grooves of an anterior causation, nor remained in the dead-lock of an unchangeable status. History is not an inflexible frame-work in which all events have been shaped by necessity; it is a development of the inherent powers and capabilities of humanity, and it teaches us that new trains of causes have been originated, and new conditions have been superinduced by man. The ground-fact which underlies all the diversity, contingency, and progress which appear in the moral world is that volitional causes are equipotent and efficient for any one of the several results.[539] In moral development the progressive principle is just the freedom of the will. The facts of the inner and outer world are therefore in harmony.