 The second part of the Tractatus comprises subjects that were of major importance in the doctrine of the properties of terms. In the sixth tract, De suppositionibus, the theory of supposition is dealt with. The treatise begins with an exposition of significatio. The definition of significatio runs: significatio is the respresentation of a thing by means of a word in accordance with convention. Next it gives a definition of the related terms suppositio and copulatio, and the differences between the terms significatio, suppositio and copulatio. Of these three suppositio and significatio are the most important in Peter’s semantics. Suppositio is defined as the acceptance of a substantive verb for some thing. Suppositio is dependent on significatio, because supposition can only occur via a term that already has some significatio. Put in other words, significatio pertains to a word by itself, and supposition to a term as actually used in some context.