When I speak of parts of the world, you must not think merely of geographical parts, but you must think farther until you arrive at the insight that stars and bricks, matter and force, in short all parts of the world are world parts.
The logical difficulty may be principally traced to the lack of familiarity with the comprehensive categories. It will be clear to you that thinking and being, phenomenon and truth, etc., are conceptions of the widest scope. So you may have some difficulty in distinguishing between concepts of truth, and true concepts. And yet this is the same as making a distinction between the general class of herbs and its individual species. The mere intercourse with such comprehensive concepts as truth, existence, universe, is an excellent school of intellectual enlightenment.
Perhaps you may object to the deviation of a science devoted to the special study of the faculty of thought into such fields as existence or truth. But a logic confined to an analysis of the faculty of understanding would be narrow compared to one representing this faculty of understanding at work in real life. If the science of the eye were to treat only of the various parts of the eye without considering the things outside connected with its function, the light, the objects, in short, the vision of the eye, it would be more an anatomy of the eye than a general science of the eye. At all events a science which represents not alone the subjective faculty of vision, but also the living activity of the eye, the objective field of vision inseparable from the subjective faculty, is a far more comprehensive instruction, a higher enlightenment of the human brain.
In my opinion, logic should not so much treat of the analysis of the intellectual subject as of the purpose and object of the faculty of thought, its culture, which is not accomplished by the intellect itself, but by its connection with the world of truth, its interrelation with the universal existence.
What can a logic accomplish which divides thought into analytical and synthetical thoughts, which speaks of inductive and deductive understanding and of a dozen other kinds, but which finally declines to meet the question of the relation of thought and understanding to truth, and fails to indicate what and where is divine truth and how we may arrive at it?
Pilate, the typical sceptic, shrugs his shoulders; the clergymen make a mystery of divine truth; the natural sciences care only for the true conceptions, but naught for the concept of truth; and then the special science of understanding, formal logic, tries to refer its task to philosophy or world wisdom.
I have already pointed out that the titles of the principal works on philosophy indicate that the whole world wisdom turns around the question: How can our brain be enlightened, how can it arrive at truth? The naturalists answer that this can be accomplished by special studies, and they are frequently opposed to philosophical research which makes general truth its main object, and belittle it. You will readily see that this is a mistake when you consider that, to illustrate, a machine or an organism as a whole is still something more than a mere sum of its parts.
No matter how well you may know each single part, yet you will not understand the whole machine or organism by this means alone. The universe is not an aggregation of unorganized parts, but a living process which must be understood not only in its parts but also as a whole. We may pass for the moment the question whether the Milky Way may be dissolved into stars, and whether the stars may become globes like our Earth which may develop plants, animals, and intelligent beings. The thing which is evident is that there is a process of development, that all nature takes part in this movement, that the universe is a whole without end, composed of an infinite number of parts; a coming and going, an eternal transformation, which is always identical with itself and always the same world. What all this would be without our eyes and ears and without the intellect by means of which we use eyes and ears, what the world "in itself" is, that is a senseless and transcendental speculation.
The science of logic must deal only with the actual world which is inseparable from us and from our thoughts.
This world which we hear, see, smell, in which we live and breathe, is the world of truth or the true world. That is a fact. Must I prove this? And how is a fact proven? How do we prove that a peach is a delicious fruit? One goes and eats it. In the same way, you may now go and enjoy life, of course in a rational manner, and I am convinced that your own love of life will tell you that it is proof positive of the truth of the world, of its actuality.