Understanding or knowledge, thinking, perceiving, reasoning, must, for the purpose of investigation, not be excessively separated from other phenomena. In a way, every object which is chosen for special study is isolated. In saying, "in a way," I mean that the separation of the objects of study from other world objects must be consciously moderate, not exaggerated. The separation of the intellect from other objects or subjects when investigating them, must be accompanied by the recognition that such a separation is not excessive, but only formal. In separating a board, for the purpose of studying its condition, from other boards or things and finding that it is black, I must still remember that this board is black only on account of its interdependence with the whole world process; that the blackness which it possesses is not of its own making, but that light, and eyes, and the whole cosmic connection belong to it. In this way every special perception becomes a proportionate part in the chain of universal perceptions, and this again a proportionate part of the universal life. That this evident universal life is not a mere semblance, not a ghost, not a baseless imagination, but the truth, is made evident to the thinking man by his consciousness, reason, common sense. True, he has been deceived by them, sometimes. But it requires no logic, no syllogistic proof, to know that they are telling the truth in this respect. It is nevertheless important to give this proof, because by it the peculiar nature of our intellect is revealed, of the object the study of which is the special concern of philosophy. This proof, that the universe is the universal truth, was first attempted by philosophy in an indirect way, by casting about in vain for a metaphysical truth. The philosopher Kant was no doubt the thinker who confined the use of understanding most strictly to the domain of experience. Now, if we recognize that this field is universal, we become aware that the assumed Kantian limitation is not a limitation at all. The human mind is a universal instrument, the special productions of which all belong to general truth. Though we make a distinction between the doubtful and the positive, the outcome of philosophy teaches us that it must be no excessive distinction, but must be backed up by the consciousness that all evidence is composed of probabilities, of phenomena of truth, of parts of truth.