After the third letter had acquainted you with the fact that the subject of logic has a certain religious flavor, the two subsequent letters endeavored to show that the logical subject is interconnected with the universal existence of the world, that the faculty of thought is an inseparable part of actual truth. In the vernacular of theology my last two letters have represented the human mind as a part of the living true God.
Christianity teaches: God is a spirit and who would worship him must worship in spirit and in truth.
And logic teaches: The spirit is a part of universal existence. Whoever worships the spirit, is an idolator, for he worships a part and misunderstands the whole truth. Truth itself is identical with the universal existence, with the world, and all things are simply forms, phenomena, predicates, attributes, passing expressions of it. The universal existence may be called divine because it is infinite, being the alpha and omega which comprises all things as special truths. The intellect is such a limited part among other special parts of divine truth, and the latter is frequently called world without any bombastic emphasis.
Undoubtedly, every science, profession and trade can say the same thing of its object. The blue sky and the green trees are divine parts. Everything is interrelated and connected. If that were a good reason for not making any subdivisions, every part and description would become endlessly tiresome.
However, the specialty of logic is the cosmic sum of all truths, because it aims at a general elucidation of the nature of the human brain. This purpose is not so well served by an accumulation of other knowledge as by the general understanding of truth.
Logic, which seeks to enlighten the mind for the purpose of scientific thinking, does not so much treat of true conceptions as of the general and absolute conception of truth which is inseparably linked to the infinite universal life.
If you wish to think scientifically, you will first of all strive after clear ideas. And yet your head may be quite clear in regard to everyday things, without getting any nearer to general clearness. Nor is such clearness obtainable by the accumulation of mere special knowledge, for even if you were to grow in wisdom to the end of your days, nevertheless the fountain of wisdom, the universe, is inexhaustible and your brain will remain imperfectly informed or unclear as before. Yea, even the smallest part of the world is so inexhaustible that the most talented can never acquire all the knowledge necessary to understand entirely even the most minute object. The strongest microscope cannot see all there is to see in a drop of water, and the wisest man can never learn all there is to shoemaking.
You can see by all this that the scientific use of our intellect is furthered by special knowledge only in the corresponding details. For this reason it does not satisfy us to have some logicians tell us how many kinds of concepts, judgments and conclusions are contained in our intellect. These are special details of logic. But the thing of first importance for the student of logic is the elucidation of the universal concept of truth, not the accumulation of special truths.
Special truths enlighten the intellect. But the understanding that all specialties are connected with one another by one monad or unit which is truth itself gives us a certain general enlightenment which certainly does not render any special research unnecessary, or take the place of it, but which may well serve as the foundation of all research, which may therefore be called a fundamental assistance.
I may remark in passing that the understanding of logical science is rendered especially difficult by the fact that the unpracticed understands all terms and concepts only in their narrow popular meaning, while the subject matter leads up continually into the widest fields.