In order that you may understand the interrelations of the things of the universe, I must warn you against this exaggeration and prove that the intellect has a real existence which is connected with the universe or reality. Botany, which occupies itself with plants, does not only teach us to divide them into classes, orders, and families, but it also does more by showing us what place in the entire realm of nature is occupied by the vegetable kingdom, by pointing out the differences which distinguish the plants from the inorganic mineral kingdom or the organic animal kingdom. Formal logic similarly dissects the spirit into its parts, makes distinctions between conceptions, ideas, judgments, conclusions, divides these into subdivisions, classifies conceptions according to species, separates abstract and concrete thought, knows many varieties of judgments, registers three, four, or more modes of conclusion. But at the same time this formal logic recoils from touching on the question as to how the universal spirit is related to the universe, what role it plays in the general existence, whether it is part and parcel of nature or transcendental. And yet this is the most interesting part, the part which logically connects the intellect and the science of the intellect with all other sciences and things. Logic must teach us how to distinguish. It is not a question, however, of distinguishing sheet iron from gold, or a greyhound from a pug-dog, for this is done by special lines of knowledge. Logic must rather enlighten us about that part of the faculty of distinguishing which is generally required in all branches of knowledge, whereby truth and error, imagination and reality are recognized. To this end I feel impelled to advise you not to overlook that even error and imagination belong to the one infinite and absolutely coherent reality. For the purpose of distinguishing true imagination from actual reality, it must be remembered that just as rye bread and cream puffs agree in belonging to the general category of baker's products, so imagination and truth, thought and reality, are two different kinds of the same nature. To sum up the contents of this letter, let me point out that its beginning shows the connection of the intellect with the development of the people, while its conclusion explains the wider connection of the mind with the universal existence. FIFTH LETTER A man not trained in logical thinking is handicapped by the absence of a monistic method of thought. Monistic is synonymous with systematic, logical, or uniform.