We have already expressed the opinion that the scholastics as represented by St. Thomas really mean by their phantasms and intelligible species, or intermediary ideas by which we attain to the knowledge of sensibles and intelligibles, simply the mediating light furnished by God himself, who is himself light and the Father of lights. In this case the light is objective, and by illumining the object renders it intelligible, and at the same time the subject intelligent. But Reid, who denied intermediary ideas, seemed to suppose that the light emanates from the subject, and that it is our powers that render the object intelligible. Hence he calls the categories first principles of science, constituent principles of belief, or common sense, and sometimes constituent principles of human nature. He seems to have supposed that all the light and activity is on the side of the subject, forgetting that the light shineth in darkness, and the darkness comprehendeth it not, or that the light shines, and the darkness does not compress it, or hinder it from shining, without our perceiving it or the objects it illumines. Kant, a German, but, on one side, of Scottish descent, adopts the principles of Reid, but sets them forth with greater precision and more scientific depth. Denying with Reid the mediating ideas, he makes the categories, which, according to Aristotle, are forms of the _mundus logicus_, or intermediary world, forms of the subject or the subjective laws of thought. He does not say with Rosceline that they are mere words, with Abelard that they are mere conceptions, nor with St. Thomas that they are, taken as universals, conceptions, _cum fundamento in re_, but forms of the reason, understanding, and sensibility, without any objective validity. They are not derivable from experience, because without them no experience is possible. Without what he calls synthetic judgments _à priori_, such as, Every phenomenon that begins to exist must have a cause, which includes the judgment of cause, of universal cause, and of necessary cause, we can form no synthetic judgment _à posteriori_. Hence he concludes that the categories, what some philosophers call first principles, necessary truths, necessary ideas, without which we do not and cannot think, are inherent forms of the subject, and are constitutive of reason and understanding. He thus placed the intelligibleness of things in the elemental constitution of the subject, whence it follows that the subject may be its own object, or think without thinking anything distinct from himself. {153} We think God, man, and nature, not because they are, and think them as we do not because they are really such as we think them, but because such is our mental constitution, and we are compelled by it to think them as we do. This the reader must see is hardly disguised scepticism, and Kant never pretended to the contrary. The only escape from scepticism, he himself