The positive outcome of philosophy, then, in its abstract outline, is at present the doctrine that the general must be conceived in its relation to its special forms, and these forms in their universal interconnection, in their qualities as parts of nature in general. True, such an abstract outline reveals very little. In order to grasp its concrete significance, we must penetrate into its details, into the special aspects of this doctrine.
The title of "Critique of Reason," which Kant gave to his special study, is at the same time a fitting term for all philosophical research. Reason, the essential part of the human soul, raises the critique of reason, the science of philosophy, to the position of the most essential part of psychology.
But why do we call this the most essential part? Is not the material world and its understanding as essential as reason, as intellect, which bends to the task of exploring this world? Surely, it is, and I do not use the word essential in this sense. I call the intellect the most essential part of the soul, and the soul the most essential part of the world, only in so far as these parts are the special condition of all scientific study and because the investigation of the general nature of scientific study is my special object and purpose. Whether I endeavor to explain the general nature of scientific study, whether I investigate the intellect or the theory of understanding, it all amounts to the same thing.
Let us approach our task once more from the side of Fechner's universal soul. With his extravagant animation of all things, with his plant, stone, and star souls, he can help us to prove that the general nature of that particle of soul which is called reason, intellect, spirit, or understanding, is not so extraordinarily different from the general nature of stones or trees as the old time idealists and materialists were wont to think.
As I said before, Fechner is a poet, and a poet sees similarities which a matter-of-fact brain cannot perceive. But at the same time we must admit that the matter of fact brain which cannot see anything but mere distinctions is a very poor brain. The philosophers before me have taught me that a good brain sees the similarities and the differences at the same time and knows how to discriminate between them. A sober poetry and the combination of poetic qualities with a comprehensive and universal levelheadedness and discrimination, these are the marks of a good head. Still the poorest as well as the most talented brains partake of the general brain nature, which consists in the understanding that like and unlike, general and special, are interrelated. The one is never without the other, but both are always together.
If the distinction between men and stones is so trifling that a talented brain like Fechner's can justly speak of them both as being animated, surely the difference between the body and soul cannot be so great that there is not the least similarity and community between them. However, this escaped Fechner's notice. Is not the air or the scent of flowers an ethereal body?
Reason is also called understanding, and it is a positive achievement of philosophy to have arrived at the knowledge that this understanding does not admit of any exaggerated distinctions. In other words, all things are so closely related that a good poet may transform anything into everything. Can natural science do as much? Ah, the gentlemen of that science are also progressing well. They transform dry substance into liquid, and liquid into gas; they change gravity into heat and heat into mechanical power. And they are doing this without forgetting to discriminate, as happened to our Fechner.
It is not enough to know that the body has a soul and the soul a body, not enough to know that everything has a soul. It is also necessary to discriminate between the peculiarities and details of the human, animal, plant, and other souls, taking care not to exaggerate their differences to the extreme of making them senseless.
We do not intend to follow this theory of a universal soul any further. Fechner declares himself that "it must be admitted at the outset that the whole question of a soul is a question of faith."... "Analogy is not a convincing proof."... "We can no more prove the existence of a soul than we can disprove it."
However, from the time of Cartesius it has been an accepted fact in the world of philosophers that the consciousness of the human soul is the best proof of its existence. The most positive science in the world is the empirical self-observation of the thinking soul. This subject is the most conspicuous object imaginable, and it is the positive outcome of philosophy to have given an excellent description of the life and actions of this soul particle called consciousness or understanding.