from all prejudice, and a readiness to listen to the still small voice of truth, when once it shall begin to speak in real earnest. But now, having reduced all the knowledge which comes through the ordinary channels of the senses and the faculties, to the condition of doubt and uncertainty, Descartes proceeds next to inquire, whether there is nothing whatever that can rise above it; that is, nothing to which uncertainty absolutely fails and refuses to attach itself. One thing he finds, of which we cannot possibly doubt, and that is thought itself. If I admit a thing to be true, he reasons, I can only do so by means of thinking; if on the other hand I doubt it, still this very act of doubting implies the same fact—the fact that I think. Everything else may be uncertain; even mathematical relations may prove false, because we may, for ought we know, have been so created as to exist under a perpetual delusion concerning them. But it cannot be untrue that thought itself exists. To doubt it, is still to think; so that doubt here destroys itself, and involves its own complete refutation. But thought, when once established as a fact, must imply a thinking being. In other words, the testimony of consciousness to the fact of thought, and to that of our own existence, is simultaneous and irresistible. This is the real force of the famous Cartesian formula—"Cogito, ergo sum." It never was intended by the author of it to hold good as a logical process, but was simply his mode of expressing the fundamental truth, that the moment there are phenomena of any kind in the consciousness, that moment we become cognizant of our own existence. The question was, where are we to find the first ground of certitude? The reply of Descartes is—I, for my part, find it in the veracity of my own consciousness—"Cogito, ergo sum." Having now found his starting-point, Descartes goes on to build up his system step by step. I think, is equivalent to saying, I experience ideas. Many of these ideas, we have good reason to know, are delusive. The question therefore next to be decided is—are they all so? or is there any criterion whatever by which we can distinguish the true ones from the false? Supposing we go back once more to the first point which arrested us, namely, the fact that I think, what, after all, is the evidence of this? The only ground on which I can affirm it with the most unwavering confidence is—that I have a perfectly clear and distinct consciousness of it. Perfect clearness, therefore, is in this case at least the test of validity. May it not be so in all others? But an objector will say—Do I not find, then, the most perfect clearness attaching to any ordinary sensation or perception? Have I not a perfectly clear idea of yonder chair or table? No, says Descartes; by no means. Consciousness affirms that you have an idea of it at present in your mind; but it affirms no more. It says nothing whatever as to its objective reality. This is a conclusion you draw from the idea, and possibly draw quite incorrectly, as is the case, indeed, in dreams and other mental illusions. Well but, the objector may go on to say, you must at least admit that I have a perfectly clear idea of a square, a triangle, a numerical equation, and other mathematical facts. Yes, replies Descartes, you have; and this would be quite decisive of their truth, but for one fatal flaw in the evidence. What if God has so created you that these ideas, although clear, should be after all deceptive? It is evident, from this obstacle to our further progress, that the existence of a God of perfect truth and rectitude must be fairly established, or human knowledge must be henceforth renounced as an impossibility.
Now it is incontestable, argues Descartes, that the idea of an all-perfect Being really exists in our minds, and that this idea is an extremely distinct one. But how could such an idea originate? We do not manufacture ideas out of nothing. We may compound them, indeed, of elements already existing within us; but even then the materials must be derived from something which is objective to ourselves, and which answers fully to the internal mental phenomenon. Now, as it is incontestable that we do actually possess within us the distinct idea of a being infinite, eternal, immutable, independent; and as the elements of such an idea could not come either from our finite selves, or from the finite world without us, we conclude, that it must come from the being himself who perfectly answers to the idea. This is what we may term the psychological proof of the existence of God. Put it into a more modern form, and it simply amounts to this—that the idea of the infinite and the absolute is so manifestly and indelibly impressed upon the human consciousness, and that the want of it would leave such a void in the human mind, that we cannot doubt of its fundamental reality. To this psychological proof, Descartes adds two others, which are not to be regarded as fundamentally different, but as simply presenting the same argument in another form. The second proof is put as follows—I exist, and that not self-caused, but derived from some source out of myself. This source cannot be in any object around me, not even in my parents; for, as I have the idea of all possible perfections within me, I cannot come from any source less perfect than my own ideas; that is, less perfect than God. The third proof attempts to show that the existence of God is as certain as a mathematical axiom or demonstration. Every mathematical property of which I am conscious in connection with any mathematical figure, must really belong to that figure. Thus my reason perceives that the three angles of a triangle are equal to two right angles; and this property I know belongs to the triangle itself, because my reason perceives it in connection with every such figure. Now I have the idea of an all-perfect being; but amongst the properties belonging to this idea, is that which we term existence. Hence existence can be predicated of God with the same rational certainty as the above mathematical property can be predicated of a triangle. The vice in all these demonstrations is, that they all turn upon the mere metaphysical conception of a deity; they do not bring us at all into contact with a divine personality, in which we can trace those moral attributes, which form everything that renders theism a blessing and a joy to the human soul.
The existence of God being proved, and all possible perfection being added to it as a necessary corollary, a tolerably broad platform is laid for erecting the edifice of human knowledge still further. First of all, mathematical truth is secured; for here the ideas are perfectly distinct, and the perfections of the Deity forbid the supposition that we should be the subjects of any systematic deception. Next we can advance by the light now kindled into the region of mind, and gain knowledge of much which it concerns us to know here. The testimony of consciousness being again appealed to, it appears that we can distinguish quite clearly three classes of mental facts—namely, judgments, volitions, and emotions. In this division of mental phenomena, we may remark in passing, there is very clear foreshadowing of the main outlines of our more modern psychology. Looking still further at the first of these divisions, Descartes again separates all our judgments, or what is the same thing, our ideas into three classes; namely, innate ideas, ideas which come from without, and ideas which come from ourselves. The doctrine of innate ideas is one of the main points in the Cartesian philosophy, and has been the arena of the sharpest metaphysical contests. To do our author justice, he does not regard these ideas as ready-made notions constantly present to the mind; he merely affirms that there are certain germs of thought which originally exist; that these germs are unfolded by the force of circumstances; and that, when once unfolded, the mind has the power of reproducing them at any time by an effort of its own will. So far he has clearly apprehended the nature of what we may term the à priori element in the human mind. But taken in connection with his views of the divine sovereignty, this whole doctrine of innate ideas becomes stiffened into a dogma as false as it is injurious. As our nature comes from God, so, he affirms, must our ideas. But, as God is supreme, he has the absolute power to change or modify them as he pleases. Hence they do not represent to us any fixed and immutable truth, but only certain points of view with which it may please the will of the Creator to furnish us. Thus the human mind, in all its deeper movements, becomes simply the instrument of the divine will, and the human reason becomes absolutely absorbed in the supremacy of the divine influence. In this thought we have the germ of all the pantheistic speculations of modern philosophy. Starting from the Cartesian doctrine of innate ideas, we may trace its development through Malebranche to Spinoza, and from Spinoza onwards to all the subsequent vagaries of the full-blown idealism of Germany.
Amongst the different classes of ideas to which reference has been made, we turn next to those which come from without. We have the ideas of extension, of substance, of motion, of colour, of smell, &c.—ideas which we are perfectly conscious do not originate from our own will. But why may we not regard them as wrought in us by the direct power of the Deity? and what reason have we to believe in any objective reality answer-
