According to Ernst Cassirer, the problem and the concept of the symbolical function may be considered as the core of the philosophical inquiry (Cassirer, 1985, p. 1). To be sure, many philosophers of the 20th century agree with Cassirer's point of view. As Alfred North Whitehead remarked, 'symbolism" does not constitute an idle fantasy, but is immanent to human existence (Whitehead, 1958, p. 61–62). Nevertheless this "immanence" can be interpreted in different ways. The relationship of the symbols with reality, the role played by symbols in our mental activity, the various manners of "constructing the world" on the basis of human symbolisation, are all challenges to most of the philosophical disciplines.¹ This is particulary true in the field of epistemology. Questions such as the meaning of symbols within scientific knowledge, their epistemological status, whether and to what extent they are constitutive conditions of experience, and eventually the possibility of considering the 'symbolic form" of knowledge as an unavoidable semiotic function of the scientific grasping of reality are problems concerning not only the "archeology" of the philosophical tradition, but also and firstly the philosophical tasks as well as our contemporary debates.