One of the first requirements for the education of the object of philosophy is to recall its various names. The understanding, or the power of knowledge, is also called intelligence, intellect, mind, spirit, reason, power of cognition, of conception, of distinction, of imagination, of judgment, and of drawing conclusions. The attempt has frequently been made to analyze understanding or to dissect it into its various parts and to specialize them by the help of those names. Especially logic knows how to give particular explanations of what is imagination, a conception, a judgment, and a conclusion. It has even divided these sections into subsections, so that a trained logician might reproach me with being ignorant for applying various names to intelligence, because only the common people confound those names and use them as synonyms, while science has long used them in their proper order for designating special parts of intelligence. To such a reproach, I answer that Aristotle and the subsequent formal logicians have made some pretty pointed observations and excellent arrangements in this field. But these proved to be premature or inadequate, because the observations on which the ancient intellectual explorers relied were too scanty. This scantiness of the observations made in regard to intelligence, and by intelligence, has kept the human race in the mazes of intellectual bondage and by this mysticism has even prevented the most advanced minds from penetrating deeper into this obscure question. The history of philosophy is not the history of a useless struggle, but yet a history of a hard struggle with the question: What is, what does, of what parts consists, and of what nature is understanding, intelligence, reason, intellect, etc.? So long as this question is unsettled, the questioner is entitled to dispense with any and all sections and subsections of the intellectual object and to regard the various names as synonymous. The main accomplishment in the solution of this question is the ever clearer and preciser knowledge of our days that the nature of the human intellect is of the same kind, genus or quality as the whole of nature. In order that the theory of understanding may be able to elucidate this point, it must divest itself, more or less, of the character of a speciality and occupy itself with all of nature, assume the character of cosmogony. It is principally an achievement of philosophy that we now know definitely and down to the minutest detail that the human mind is a definite and limited part of the unlimited universe.