Semantic relations have long played an important role as explanatory constructs in psychological and linguistic theories. This use of relations as theoretical primitives has obscured the fact that semantic relations are themselves concepts with interesting properties that are in need of explanation. The representation of semantic relations in memory must be explained, in the same way as the representation of other concepts, in terms of more basic meaning elements that are common to a variety of different concepts (Lyons, 1977, p. 317). In this chapter I examine two types of evidence for these claims. First, semantic relations are like other concepts in exhibiting a typicality gradient, in permitting similarity comparisons, in being lexicalized, and in being instantiated by context. Second, logical properties of particular semantic relations derive from the relation elements of which they are composed. Whereas the logical properties of semantic relations seem to set relations apart from other concepts, I argue that the complex patterns of transitivity found among inclusion relations can only be explained in terms of the more basic relational elements of which the relations are composed.