Did Aristotle, with his categories, classify only expressions or also something extralinguistic? In the second case his classification seems to be not exclusive, at least if the usual universes of discourse are considered. However, if we use certain enlarged universes, which may have more than one individual for each individual of the usual universes, we may construct exclusive general classifications that approach the aristotelian categories. The latter ones should then be considered second order classes that classify classes of individuals. If (...) the individuals are taken from one of the indicated enlarged universes, we can obtain the exclusivity that we do not have for the usual universes. (shrink)

A new essay to analyse the demonstration which Aristotle gave of Barbara ACP is realized with the techniques of mathematicallogic. The critical points are indicated; based on them it is considered that Aristotle’s proof is not conclusive.

Since antiquity many philosophers and grammarians were looking for what is “behind” the particular grammars, for something like “the unchangeable principles common to all languages”. Even limitingourselves to the most concrete aspects of such a general grammar, we may ask whether there is something realizable among the risky hipotheses and the vague projects.In this paper we do not try to discover something more or less hidden in the particular grammars, but to show, in a very general way, some directions for (...) constructing, eventually, an universal grammar. Four approaches are mentioned:(1) artificial universal languages like Esperanto,(2) systems of automatic analysis of a language,(3) programming languages,(4) the first-order systems of logic.It is shown how those approaches (and the experiences acquired in working with them might be combined; but wether this combination produces interesting results and brings us nearer to an universal and rational grammar of our computerized epoch is an open question, which can be answered only by practical experience. (shrink)