equivalent to saying, " I think in one particular way, therefore I exist." But it is not thinking in a particular way, but thinking in general that is co-extensive with my existence. I am not always conscious of walking, or of any other special state or object, but I am always con scious, for except in consciousness there is no ego or self, and where there is consciousness there is always an ego. Do I then always think, even in sleep, asks the objector; and Des Cartes exposes himself to the criticisms of Locke, by maintaining that it is impossible that there should ever be an interval in the activity of consciousness, and by insisting that as man is essentially a thinking substance, the child thinks, or is self-conscious, even in its mother s womb. The difficulty disappears when we observe that the question as to the conditions under which self-con sciousness is developed in the individual human subject, does not affect the nature of self-consciousness in itself, or in its relation to knowledge. The force of Des Cartes s argument really lies in this, that the world as an intellig ible world exists only for a conscious self, and that there fore the unity of thought and being in self-consciousness is presupposed in all knowledge. Of this self it is true to say that it exists only as it thinks, and that it thinks ahvays. Cogito ergo sum is, as Des Cartes points out, not a syllogism, but the expression of an identity which is discerned by the simple intuition of the mind.[1] If it were otherwise, the major "or/me quod cogitat existit" would require to have been known before the minor " cogito" ; whereas on the contrary it is from the immediate consciousness of being as contained in self-consciousness that that major can alone be derived. Again, when Hobbes and others argued that thinking is or may be a property of a material substance, Des Cartes answers that the question whether the material and the thinking substance are one does not meet us at the outset, but can only be solved after we have considered what is involved in the conception of these different substances respectively.[2] In other words, to bogin by treating thinking as a quality of a material substance, is to go outside of the intelligible world for an explanation of the intelligible world, it is to ask for something prior to that which is first in thought. If it be true that the consciousness of self is that from which we cannot abstract, that which is involved in the knowledge of anything, then to go beyond it and seek for a reason or explanation of it in anything else is to go beyond the beginning of knowledge ; it is to
ask for a knowledge before knowledge.Des Cartes, however, is himself unfaithful to this point of view; for, strictly taken, it would involve the consequence, not only that there is nothing prior to the pure conscious ness of self, but that there can be no object which is not in necessary relation to it. Hence there can be no absolute opposition between thought and anything else, no opposi tion which thought itself does not transcend. But Des Cartes commits the error of making thought the property of a substance, a res cogitans, which as such can immediately or directly apprehend nothing but thoughts or ideas ; while, altogether outside of these thoughts and ideas, there is another substance characterized by the property of extension, and with which thought has nothing to do. Matter in space is thus changed, in Kantian language, into a " thing in itself," an object out of all relation to the subject ; and on the other hand, mind seems to be shut up in the magic circle of its own ideas, without any capacity of breaking through the circle or apprehending any reality but itself. Between thought and being, in spite of their subjective unity in self-consciousness, a great gulf seems still to be fixed, which cannot be crossed unless thought should become extended, or matter think. But to Des Cartes the dualism is absolute, because it is a presupposition with which he starts. Mind cannot go out of itself, cannot deal with anything but thought, without ceasing to be mind ; and matter must cease to be matter ere it can lose its absolute externality, its nature as having paries extra partes, and acquire the unity of mind. They are opposed as the divisible and the indivisible, and there is no possible exist ence of matter in thought except a representative existence. The ideal (or, as Des Cartes calls it, objective) existence of matter in thought and the real (or, as Des Cartes calls it, formal) existence of matter out of thought are absolutely different and independent things.
It was, however, impossible for Des Cartes to be content with a subjective idealism that confined all knowledge to the tautological expression of self-consciousness " I am I," " What I perceive I perceive." If the individual is to find in his self-consciousness the principle of all knowledge, there must be something in it which transcends the distinc tion of self and not self, which carries him beyond the limit of his own individuality. What then is the point where the subjective consciousness passes out into the objective, from which it seemed at first absolutely excluded? Des Cartes answers that it is through the connection of the consciousness cf self with the consciousness of God. It is because we find God in our minds that we find anything else. The proof of God s existence is therefore the hinge on which the whole Cartesian philosophy turns, and it is necessary to examine the nature of it somewhat closely.
Des Cartes, in the first place, tries to extract a criterion of truth out of the cogito ergo sum. Why am I assured of my own existence ] It is because the conception of existence is at once and immediately involved in the consciousness of self. I can logically distinguish the two elements, but I cannot separate them ; whenever I clearly and distinctly conceive the one, I am forced to think the other along with it. But this gives me a rule for all judgments what ever, a principle which is related to the cogito ergo sum as the formal to the material principle of knowledge. Whatever we cannot separate from the clear and dis tinct conception of anything, necessarily belongs to it in reality; and on the other hand, whatever we can separate from the clear and distinct conception of any thing, does not necessarily belong to it in reality. Let us therefore set an object clearly before us, let us sever it in thought so far as is possible from all other objects, and we shall at once be able to determine what pro perties and relations are essential, and what are not essential to it. And if we find empirically that any object manifests a property or relation not involved in the clear and distinct conception of it, we can say with certainty that such property or relation does not belong to it except by arbitrary arrangement, or, in other words, by the external combination of things which in their own nature have no affinity or connection.
once assure ourselves of many mathematical truths ; but, as has been already shown, there is a point of view from which we may doubt even these, so long as the idea of a God that deceives us is not excluded. If it is not certain that there is a God that cannot lie, it is not certain that there is an objective matter in space to which mathematical truth applies. But the existence of God may be proved in two ways. In the first place it may be proved through the principle of causality, which is a self-evident truth. We have in our mind many ideas, and according to the principle of causality, all these ideas must be derived from something that contains a " formal " reality which corresponds to their " objective " reality, i.e., which contains at least as much
reality in its existence out of thought as they contain iu
