The theory of the syntactical categories (abridged here as "SCs") has, since the twelfth century, been a traditional part of Scholastic logic. As a matter of fact we owe the idea to Aristotle.¹ After the barbarous period which for logic constitutes the modern centuries (sixteenth century-1847), the first new logicians showed hardly any interest in it. Husserl was the first to outline at the beginning of our century a sketch of a theory of SCs.² Nearly thirty years later, St. Łeśniewski elaborated a rigorous system of it³ - but the present author knows only of one general study on that subject in existence, a paper by Professor K. Ajdukiewicz.⁴ It would seem that in spite of the brilliant development of other parts pertaining to the logical syntax, recent logicians are apt to neglect somewhat the problems of the SCs.⁵