• concepts
• contextualism
• inferentialism
• language
• logic
• quantification

The Thesis presents and defends two general ideas.
The first is that our logical concepts are constituted by their inferential role. Part I of the Thesis is devoted to the discussion of this idea.
The second is that their semantic value is fixed by linguistic context – at least in the case of the concepts’ usages in natural languages. Part II focuses on this second idea. The concept of universal quantification is the main case-study for both ideas.
The scope of both the presentation and the defense of these two ideas is different. The inferentialist idea is firstly articulated and upheld as a general view (Chapters I-III), and is then applied to a specific concept – the concept of universal quantification (Chapter IV). The contextualist idea is investigated and defended from the start with respect to the concept of universal quantification (Chapter V). The Appendix then lends some generality to the case made for semantic contextualism, by defending it against a general objection – one that does not specifically concern a contextualist treatment of the universal quantifier, and that has to do with the possibility that tokenings or utterances of a sentence in different contexts share the same content.