If the will of man is not revealed in the things which he makes, in the words which he speaks, and the thoughts which he thinks, it is difficult to know where to look for its manifestation. If, on the other hand, it is manifested in these ways, then, whether it be free or not, it is clearly uniform in its action; and the extension to it of the law of causation seems fully justified by the results. The recognition of the universality of the law of causation must not, however, be supposed to carry with it any implication that there are no differences between, say, the organic and inorganic, or that the laws of the one are identical with or deducible from those of the other; the association of ideas may be a scientific and established fact, and yet not obey the same laws as the adhesiveness of material substances. What unites all things into a continuous, coherent, and systematic cosmos, into a scientific whole, is first the fact that, whether phenomena in sense or phenomena in idea, they are all objects of thought; and next the fact that they all exhibit the universality of causation and the uniformity of nature. Whether this uniformity which binds man and nature into one consistent whole is a uniformity of will or a uniformity of necessity, is quite another question. It is a metaphysical and not a scientific inquiry; and the metaphysical answer, whatever it may be, is one for which science does not and need not pause. So long as nature is granted to be uniform, it matters not to science whether the uniformity is of necessity or is freely willed. In either case the sequences or co-existences described by science will continue, under the circumstances described, to happen as described. It is, however, commonly assumed that actions which are uniform are, by their very uniformity, proved to be necessitated; and that unless what happens was bound to happen, there can be no uniformity and no science. Hence on the one hand the recognition of the freedom of the will has been denounced as fatal to all scientific conceptions of human nature; while on the other hand the uniformity of human nature and action has been denied as being inconsistent with the freedom of the will. The one side has pointed to one set of facts, which prove irresistibly that men do will the same thing under the same circumstances. The other side has pointed to the equally undeniable fact of our consciousness of freedom.