 But there are other ways to suggest that abstract objects have existence conditions that demand little of the world. For example, Linsky &amp; Zalta (1995, 532) argued that the mind-independence and objectivity of abstract objects isn’t like that of physical objects: abstract objects aren’t subject to an appearance/reality distinction, they don’t exist in a ‘sparse’ way that requires discovery by empirical investigation, and they aren’t complete objects (e.g., mathematical objects are defined only by their mathematical properties). They use this conception to naturalize Zalta’s comprehension principle for abstract objects.