In spite of the fact that the mathematical theory of information was formed in connection with the problems of technical transmission of data (when data could consist of fully nonsensical string of nonsensical words), it is possible to show that its main principles are not so distant from the logical structure of pre-scientific (comon sense) understanding, as applied by people in the frame of the Lebenswelt, as it could seem. E. g., Ashby's theory of variety is compatible with the structure of definition in classical logic. Moreover, the first attempt at the quantification of information took place in classical (Platonic) ontology which was a reflection of the structure of pre-scientific understanding; starting from his conception of the ANAMNESIS, according to which we can have an a priori cognition of summum genus, he tried to determine the quantity of information (measured by differences) as being comprehended in generic essences and species. Shannon's formula for the quantification of information can be interpreted ontologically, too, but the ontology which is adequate to this combines an empiricist concept of mutually independent elements of experience with the combinatorial approach first outlined by R. Lullus. In accordance with this ontological interpretation there exists a possibility to express the quantity of information as a function of the quantity of elementary differences (which is in harmony with Bateson's definition of information). The ontological interpretation of the basic principles of the theory of information eliminates the "alienation" between it and man's pre-scientific (common sense) orientation in the world, enables to avoid both subjectivist and objectivist misconceptions of the status of information, and, finally, leads to the identification of information with potential negentropy.