The dissertation relates second Wittgenstein s considerations on following rules with his criticism about the extensional treatment of the infinite as actual totality. In the first chapter, a presentation of Wittgenstein s criticism of the mentalist solution pattern for the determination of the meaning is followed by an account of what is taken to be the heart of the Private Language Argument. On that basis, it is argued that the communitarianist solution, formulated in terms of the confirmation of an independent pattern, cannot be consistently attributed to Wittgenstein. In the second chapter, the historical antinomy between the infinite as potential and the infinite as actual is introduced. Some aspects of Cantor s and Dedekind s approaches, as well as Wittgenstein s criticism of those, are also presented. In the third chapter, the connection between Wittgenstein s criticism of the treatment of the infinite as extensional actuality and the question of linguistic generality is explored, and the normative character attributed by Wittgenstein to mathematical propositions is highlighted. It is shown that, according to Wittgenstein, the conceptual difference between finite and infinite expresses the difference between empirical and grammatical contexts. The infinite as expression of generality could not be treated as susceptible to extensional description without bringing about confusion, and it should, therefore, be thought of solely in a normative context, as a rule. The problem of the determination of a rule is thus retaken in the context of the discussion on mathematical proof, and the notion of surveyability is analysed. In the fourth chapter, the notion of family resemblances is considered. The central aspects of Wittgenstein s approach to the problem of the determination of a rule - the abandonment of extensionality and the univocality of meaning - are emphasised. Instead of classes or elements primarily determining the relationship among the instances of a rule, the relationship itself would constitute such instances, and such internal relationship would be established by linguistic usage itself. Finally, in the conclusion, a general reconsideration of what was discussed is carried out, starting from the relationships between circularity and generality.