According to Mivart, the groundwork of science consists of truths which can not be obtained by reasoning, and can not depend for their certainty on any experiments or observations alone, since whatever truths depend upon reasoning can not be ultimate, but must be posterior to, and depend upon, the principles, observations, or experiments which show that it is indeed true, and upon which its acceptance thus depends. The groundwork of science must therefore be composed, he says, of truths which are self-evident; and he assures us that, if this were not the case, natural knowledge would be mere "mental paralysis and self-stultification." He would tell the wayfarer who, having been lost among the mountains, comes at last upon a broad highway winding around the foothills and stretching down over the plain to the horizon, that an attempt to go anywhere upon this road is "mere paralysis," unless he knows where it begins and where it ends. He would have told the ancient dwellers upon the shores of the Nile that their belief that they owed to the river their agriculture, their commerce, their art and science, and all their civilization, was mere self-stultification, because they knew nothing of its sources in the central table-land. May not one believe, with Mivart, that the scientific knowledge which arises in the mind by means of the senses through contact with the world of Nature, thus arises by virtue of our innate reason, and yet find good ground for asking whether physical science may not have something useful and important to tell us about the mechanism and history of this innate reason itself? Is proof that our reason is innate, or born with us, proof that it is ultimate or necessary or beyond the reach of improvement and development by the application of natural knowledge? May not this reason itself prove, perhaps, to be a mechanical _phenomenon_ of matter and motion, and a part of the discoverable order of physical causation; and may not science some time tell us how it became innate, and what it is worth? Questions of this sort are easy to ask but hard to answer; for many hold our only way to reach an answer to be _to find out_ by scientific research and discovery. While this method may be too slow for _a priori_ philosophers, may it not be wise for those who, being no philosophers, know of no short cut to natural knowledge, to admit that, while they would like to know more, they have not yet learned all there is to learn? If this suspension of judgment is indeed self-stultification, the case of many students is hard, though they may not really find themselves so helpless as they are told that they must be; for he who is told by the learned faculty that he is paralyzed need not be greatly troubled if he finds his powers for work as much at his command as they were before.