Every thing, every sense perception, no matter how subjective or shortlived it may be, is true, is a certain part of truth. In other words, the truth exists, not only in the general existence, but every concrete existence has also its own distinct generality or truth. Every object, whether it be a mere passing idea, or a volatile scent, or some tangible matter, constitutes a sum of manifold phenomena. The faculty of thought turns various quantities into one, discerns the equality in different things, seeks the unity in the multiplicity. Mind and matter have at least actual existence in common. Organic nature agrees with inorganic nature in being material. It is true that there are wide divergences between man, monkey, elephant, and plants attached to the soil, but even greater differences are reconciled under the term "organism." However much a stone may differ from a human heart, thinking reason will discover innumerable similarities in them. They at least agree in being matter, they are both visible, tangible, and may be weighed, etc. Their differences are as manifold as their likenesses. Solomon truly says that there is nothing new under the sun, and Schiller also says truly that the world grows old and again grows young. What abstract thing, being, existence, generality is there that is not manifold in its sense manifestations, and individually different from all other things? There are no two drops of water alike. I am now in many respects different from what I was an hour ago, and the likeness between my brother and myself is only relatively greater than the likeness between a watch and an oyster. In short, the faculty of thought is a faculty of absolute generalization, it classes all things without exception under one head, it comprises and understands everything uniformly, while sense perceptions show absolutely everything in a different, new and individual light. If we apply this metaphysics[1] to our study, the faculty of thought, we see that its functions, like all other things, are material manifestations, which are all equally true. All manifestations of the mind, all ideas, opinions, errors, partake of a certain truth, all of them have a kernel of truth. Just as inevitably as a painter derives all forms of his creation from perceptible objects around him, so are all ideas, images of true things, theories of true objects. So far as perceptions are perceptions, it is a matter of course that all perceptions perceive something. So far as knowledge is knowledge, it requires no explanation that all knowledge knows something. This follows from the rule of identity, according to which a equals a, or from the rule of contradiction, according to which 100 is not 1,000.