The Metaphysics of Property Perception

Objects are particulars because they can only be present in one place at a time. By contrast, properties are usually classified as universals: one and the same property can be possessed by objects in distinct locations at the same time. Yet property instances (or ‘tropes’) are particular: they are distinguished in part by which object or location possesses them; e.g. instead of a shade of red that might be shared amongst various objects, we isolate a particular chair’s redness.

Given this distinction between universals and property instances, philosophers ask: which of these do we perceive? Some insist we perceive only property instances (e.g. Schellenberg 2010), and others only universals (e.g. Johnston 2004); a few allow that we perceive both (e.g. Almang 2016). Yet each answer seems to sit badly with other claims we are tempted to make about perception.

If we perceive only property instances, we seem hard-pressed to explain what is in common between perceiving objects of the same colour. If we perceive only universals, it becomes more difficult to accommodate the manifest particularity of perceptual experience. On the other hand, if we say we perceive both, we would need a story about the relation between the perception of items of both sorts.

A quite different metaphysical question arises when we ask whether, and in what sense, sensible properties might depend on the mind. We are tempted to say that when we perceive a chair’s shape, for instance, the chair’s having that shape does not depend upon its being perceived; i.e. the chair would have had the same shape even if we had never seen it.

Many are also tempted to say that someone who hallucinates a seemingly identical chair succeeds in perceiving the same shape as the person who perceives the actual chair. Yet if the same property (in this case a shape) can be perceived in the absence of an object, this property’s presence seems to depend wholly upon our perceiving it. Does that mean that the property is mind-dependent?

Resolving this long-standing puzzle may require revising our metaphysics of sensible properties, or a revision of how we understand the role of property perception in hallucination.