Indispensability Arguments for Non-Existents.

This essay is chiefly concerned with two fields of philosophy in which non-existent objects appear in indispensability claims for their existence, namely philosophy of mind and truthmaker theory. In the former, indispensability claims are derived from the apparent data of intentionality, understood as the mind’s direction upon objects. An intuitive survey of the apparent objects of thought will reveal an apparent array of non-existents, either coherent or incoherent. We may, for instance, apparently think of objects of fiction such as Sherlock Holmes or Pegasus, to name some famous examples from the literature. We may also apparently think of objects such as round squares or existent golden mountains, or sets of all sets that don’t contain themselves, etc. In the latter, indispensability claims are made for non-existent objects as a means for providing the grounding of the truths of our statements about the world, particularly those that are apparently negative- such as, this cat is not red, to use an example I will draw on. Truthmaker theory is abound with difficult in grounding such statements in the world without violating widely accepted precepts of a realist metaphysics. Because of this difficulty some have posited the existence of things such as absences, lacks, or negative facts. I argue that neither of the arguments given in these fields compels us to accept non-existent objects of any kind into our ontology.