In the first place, a "subject" is not a fixed, but a variable concept. In the last analysis, as we have sufficiently explained in this work, there is only one sole universal subject which is nowhere radically different.
The first principle of the old and tried Aristotlean logic tells us that a man, a subject, who is lame cannot move about with alacrity. But I have a friend who was totally lame and who today jumps about briskly; there is no contradiction in this. But if I tell another man about my lame friend and in the course of my story have this lame subject all of a sudden jumping over chairs and tables, then such a thing is inconceivable and I contradict myself. Such a contradiction is a violation of all logic, but not because agility and lameness are totally different predicates which cannot be attributed to the same subject, nor because the contradiction cannot exist. Being is full of contradictions, but they are not simultaneous or without mediation. A logical speech or story must not forget to mediate. By mediation, all contradictions are solved. And this is the outcome of philosophy.
In discordant metaphysics, being and not being are irreconcilable and mutually exclusive contradictions. Metaphysics is in doubt whether this common existence is real or only apparent, or whether there is not somewhere in a heaven above the clouds an entirely different life. But philosophy is now fully aware that even the most fictitious being is so positively real that any negation which appearances may attribute to it is outclassed by affirmation to the utter discomfiture of the former. Being and its affirmation is absolute, negation and not being are only relative. Being is everywhere and always dominant, so that there is no non-existence. Though we may say that this or that is nothing, yet we must remain conscious that anything we may call nothing is still something very positive. There cannot be any ignorance which does not at least know a little. There is no evil which cannot be transformed into good. The things that have been, will be, and are, all of them are. There is no non-existence. It is at least a word, though it does not convey any meaning. The world and our language are of so positive a character that even a meaningless word still means something. Nothing cannot be expressed.
The superstition of another "true" world which floats above this world of phenomena or is secretly hidden behind it has so vitiated logic that it is now difficult to remove the discordant metaphysical "concept of being" from the human mind. The belief in something absolutely different will not easily disappear. It is especially difficult to demonstrate that conceived things are of the same nature as real things, that both of them really belong to true nature.
Conceived things are pictures, real pictures, pictures of reality. All the limbs of an imaginary dragon are copied from nature. Such creations of imagination are distinguished from truths only by their fanciful composition. To connect nature and human life according to the given order, that is the whole function of understanding. Knowing, thinking, understanding, explaining, has not, and cannot have, any other function but that of describing the processes of experience by division or classification. The famous scientist Haeckel may call this contemptuously "museum zoology" and "herbarium botany," but he simply shows that he has not grasped the secret of the intellect, but still wonders at it in a metaphysical way, the same as his predecessors.
What Darwin ascertained about the "origin of species" and about the transitions and evolutions in organic life is a very valuable expansion of museum zoology. Whoever expects anything else from the nature of intellectual faculties, shows that he is not familiar with the outcome of philosophy, that he has not emancipated himself from the vain wondering and its accompanying edification, which the wonder of human intelligence caused to primitive ignorance.
Understanding has hitherto been in error about itself and was, therefore, inadequately equipped for the task of giving a true account of its relatives, of the phenomena of nature and life. Nevertheless it has acquired training in the course of culture and has progressively accomplished better things. Its errors have never been valueless, and its truths will never be sufficient. That this is so, is not due to the defective condition of our intelligence, but to the inexhaustibleness of being, the indescribable wealth of nature.
The self-conscious, philosophically trained understanding and intelligence has now the means of knowing that the accuracy of all investigation is limited, that for this reason all its future results will be affected by error. But a science which is backed up by such an enlightened understanding, is reconciled to its limitations and transforms them into a hall of glory. Self-conscious limitation is aware of its partnership in the absolute perfection of the universe.