But there is a difference between these two kinds of truth. The truths of the reason are clear and distinct; the truths of experience are clear but not distinct. Leibnitz is, be it observed, making a distinction between the two terms of the pet phrase of the Rationalists――“clear and distinct ideas.” He means that rational truth is so transparent that it is impossible to conceive its opposite; that empirical truth is only clear, and its opposite is thinkable. It is impossible to think that the three angles of a triangle equal anything but two right angles, but it is possible to think that its side, which is now two inches, may be four inches. Thus emerge the two logical principles upon which Leibnitz founded his philosophy: rational truths depend upon the _Principle of Contradiction_; empirical truths depend upon the _Principle of Sufficient Reason_. At first Leibnitz conceived that this distinction between truths did not apply to God, but only to man. Man must rejoice in the few rational truths in his possession and be content with merely establishing the actuality of his experiences. The divine reason can, however, see the impossibility of the opposite both in rational and in empirical truth. Later on Leibnitz conceived the distinction between the two kinds of truth to be absolute. That is, in the nature of things the two truths differ. The rational truth has no opposite, but is a _necessary_ truth; the empirical truth has an opposite, and is a _contingent_ truth. Leibnitz thus shows the fundamental principles upon which knowledge is based, but what does he say about the logical method of their combination? Nothing. No one would ever suspect from Leibnitz’s philosophical remains that he had planned a system of philosophy according to the method of Spinoza. The many pamphlets of Leibnitz on many scattered subjects show how far short he fell of his ideal of a universal philosophical calculus. He was too versatile, his interests were too diversified, to carry through so slow and plodding a task. He merely stated the principles upon which a systematic symbolic philosophy might rest, without developing these principles in a logical way. Like Bacon, Leibnitz conceived a method that was more of a hope than an accomplishment.