## ABSTRACT

Science, language, and logic are interlocking concepts in Hobbes’s philosophy. Science is a set of true sentences or propositions of a language. It consists of two parts. The ﬁrst part is a set of deﬁnitions, which are in eﬀect axioms (cf. DCo 3.9). The second part is all of the sentences that are entailed by those deﬁnitions either directly or indirectly (cf. Hanson 1990). The inferences from deﬁnitions or from intermediate sentences (theorems) to other theorems are calculations or reckonings of words, just as adding and subtracting numbers are. The calculation of words is reasoning (L 5.2); the study of reasoning is logic. Science, language, and logic, then, form a tight cluster of concepts.