When we consider the theoretical choices underlying the emergence of the various trends of formal linguistics in the twentieth century, it is now a well-known fact that Lvov-Warsaw’s polish School distinguished itself through its desire to define an algorithm which would not separate the syntactical properties of sentences from their semantic features. In parallel with the development of his algebraic model of categorial resolution, Kazimierz Ajdukiewicz (1890 – 1963) wrote several papers dealing with the semantics of natural languages in which he argued: “a language is not unequivocally characterized solely by its vocabulary and the rules of its syntax; it is also characterized by the way meaning is coordinated with its words and expressions” (1934 : 39). Now, though the grounds for such an approach were attributed to the influence exercised by Edmund Husserl’s Logical Investigations (1901), the aim of this communication is to show that they can’t be reduced to such an explanation since the way of looking at meaning defended by Ajdukiewicz is very different from the one set out in the Investigations. On one hand, Ajdukiewicz was aware that Husserl’s Bedeutungskategorien corresponded – as he wrote it – to “syntactical categories” and, on the other hand, he never thought of a platonic approach where the ideal realm of meanings (conceived as abstract kinds or species) would be governed by a priori laws, but advocated a radical conventionalism based on three kinds of rules of meaning (deductive, axiomatic and empirical). In order to identify the specificity of the theory of meaning giving rise to the development of a natural language categorial approach, I’ll begin by questioning the idea that this approach was exclusively inspired by Husserl’s point of view. To do this, I’ll study Ajdukiewicz’s semantic theory and point out the various influences that have improved it. This analysis will lead to showing the very innovative aspect of this approach to meaning which, following the contemporary logico-semantic theories, sets the notion of inference at the heart of the device allowing the calculation of meaning.