I segni della matematica: le origini della moderna simbologia

Abstract. In the collective imagination there is nothing that is less appealing than a formula that contains symbols. But even the most obtuse symbols that populate theorems and equations actually reflect very precise logical criteria. In fact I would almost say \u201caesthetic\u201d criteria, as their success, in general much more laborious than is popularly thought, is tied to their capability of \u201ccommunicating\u201d, just as in the case of a trademark or a logo. Symbols are nothing but pictorial or graphical representations that really work much better than any ordinary language-like notation. This paper concerns the rise of mathematical symbols, their day of popularity, their eventual decline. The communicative effort that the \u201cinventors\u201d of such symbols made in the past can not denied: they tried, in a certain sense, to make abstract concepts \u201cvisible\u201d, with the purpose of enlarging their circle of of users . I agree with Lancelot Hogben who said: \u201cEvery meaningful mathematical statement can also be expressed in plain language. Many plain-language statements of mathematical expressions would fill several pages, while to express them in mathematical notation might take as little as one line. One of the ways to achieve this remarkable compression is to use symbols to stand for statements, instructions and so on\u201d. But I am convicted that this argument remains true even if any connection to mathematics is overleaped. A final remarks: drawings have been used during the talk we gave, as invited speakers, on this subject at the conference Matematica e Cultura 2008 and they have been very successful