 Determinables as failing to track exact similarity. Armstrong takes “the powerful truism that universals are strictly identical in their distinct instantiations” to support the claim that “properties that are lowest determinates […] are good candidates for being universals” (1997: 49). More weakly, one might maintain that the best reason for positing properties, however understood, is as explaining exact similarity (in a given respect) between objects. Supposing so, one might moreover maintain that only determinates exist, on grounds that particulars having determinable properties might fail to exactly resemble in determinate respects (e.g., red objects might be different shades of  red).[17] 