Holes (1996-2025)

Holes are presented as philosophically puzzling entities that everyday language treats like spatiotemporal particulars - countable, shaped, located and often causally implicated - yet intuitively immaterial, paradigms of absence. Perceptual and developmental evidence shows people, including infants, detect, count and track holes as readily as solid objects, and visual factors such as convexity, contour relations and grouping influence hole perception. Key problems identified include how immaterial holes can be perceived if perception requires causal interaction, how to specify identity and persistence independently of a material host or transient guest, how mereological questions arise when holes divide or join, and whether appeals to holes are explanatorily dispensable given purely physical descriptions.

Proposed responses range from eliminating hole-talk via paraphrase to treating holes as regions or qualified portions of spacetime, as ordinary superficial parts (hole-linings), as negative parts of hosts, or as disturbances akin to knots or wrinkles. Each account encounters concrete challenges: paraphrase must manage complex quantification and shape predicates; spacetime views face relationist and rotational puzzles; hole-lining and negative-part accounts must reconcile counterintuitive semantics (e.g., making a hole as adding a part) and persistence across host change; disturbance views must specify ontological dependence. Ongoing debate centers on reconciling common-sense cognition, perceptual data, and metaphysical parsimony.