Just as the domestic cat and the panther are different species of cats and yet belong to the same genus of cats, so true and false thoughts, in spite of all their differences, are of the same genus. For truth is so great that it comprises absolutely everything. Truth, reality, the world, the all, the infinite and the absolute are synonymous expressions. A clear conception of truth is indispensable for the understanding of logic. And in the last analysis it is simply using different words for the same thing, when I base the quintessence of logic, its fulcrum, cardinal, salient, or distinctive point on the spirit intimately united to nature or on the concept of a uniform world, truth, or reality. I cannot give you a clearer view of truth than by quoting at this place the famous words of Lessing: "If God were to offer me the ever active striving for truth in his left hand and truth in his right hand, I should grasp his left and say: Father, keep truth, it is for you alone." This statement is somewhat highflown and mystical, and Lessing was no doubt somewhat embarrassed by mystical thinking. Still there is a sober truth in these words, which is quite clear and to the point. "Truth itself" is the universe, the infinite and inexhaustible. Every part of it is a finite part of the infinite and is, therefore, finite and infinite, perishable and imperishable at the same time. Every part is a separate part and connected inseparably with the whole. The human mind, among others, is such a part. The universal existence, or truth, is the inexhaustible object of the human mind. The fact that in the study of logic the human mind has itself for an object must be explained to the student by pointing out that in this case the subject and the object are both things like all other things, in other words, are a part of truth, a part of natural existence. "Truth itself" cannot be wholly conceived by the human brain, but in parts. For this reason we possess only the ever active striving for truth; for this reason, furthermore, the conception or knowledge can never be completely identical with reality, but can be only a part of it.