 The relationship between thought and reality was a focal point of Wyclif’s reflection. On the one hand, Wyclif believed that thought was linguistically constrained by its own nature; on the other hand, he considered thought to be related to reality in its elements and constitution. Hence he deemed language, thought, and external reality to be of the same logical coherence (see Conti 2006, pp. 114–18, and Spruyt 2008, pp. 24–25). Within this context, the theory of supposition was intended to explain the different roles that words (or phrases) can have in relation to language and the extra-mental world when they appear as extremes (that is, as subject or predicate) in propositions. Characteristically, his theory of supposition provides an account not only of the truth-values of a sentence, but also of its meaning; it is not therefore simply a theory of reference, but a sort of complex analysis of language viewed as a semiotic system whose unique interpretative model was the reality itself. It gives clear evidence of Wyclif’s realist choice and of his conviction that any kind of linguistic and semantic features must be grounded on ontological structures.