 According to a majority of the trope theorists, objects are bundles of tropes. The alternative is to understand the object as a complex consisting of a substrate in which tropes are instantiated. This is the minority view (defended by e.g., Martin 1980; Heil 2003; and Lowe 2006). According to Armstrong (1989, 2004)—a staunch but comparatively speaking rather friendly trope-critic—the substrate-attribute view is the superior one, even for a trope theorist. There exist several reasons to be suspicious of that claim, however (Maurin 2016). One such reason has to do with parsimony. If you adopt a substrate-attribute view, you accept the existence of substrates on top of the existence of tropes. Accepting this additional category makes at least some sense if properties are universals. For if objects are bundles of universals, then if a is qualitatively identical to b, a is numerically identical to b. That is, if object are bundles of universals, the Identity of Indiscernibles is not just true, but necessarily true (although cf. O’Leary Hawthorne 1995 for a reason against this). This is a consequence few universal realists have been prepared to accept.[32] If properties are tropes, on the other hand, then the tropes that make up one object will be numerically distinct from the tropes that make up the other, which means that the possibility of qualitatively identical, yet numerically distinct, objects is rather easily provided for. But then, if you are a trope theorist, the added cost of accepting substrates into your ontology becomes much harder to justify.