A kind of ambivalence characterizes the discussion of philosophical issues: on the one hand we are ready to admit that philosophical concepts are deeply rooted in the language in which they are expressed, and receive within this language the core of their meaning (let us only recall the often expressed claim, according to which the basic features of Western philosophy reflect to a great extent the fundamental syntactic and semantic structure of ancient Greek). On the other hand we are equally convinced that these concepts may, nevertheless, receive a technical characterization, which is more or less stable and universal. Perhaps it may not be so in the sense that it is independent of any linguistic influence, but at least in the sense that it may be "neutral' with respect to the historically existing spoken languages, and only depend on the evolution of a disciplinary "philosophical language'. This conviction is an obvious precondition for making sense of any professional work in philosophy which is expected to reach a certain level of universality without being inexorably affected by idiomatic limits; and it is also supported by the concrete fact that we are able to understand philosophical texts belonging to quite different ages and languages, and to engage in philosophical discussions over the existing linguistic frontiers.