The conditions of experience › What makes this one object?

A cup sits on your desk. You see its handle, look away, and then see its other side. You take these views to belong to one object that remains there while your attention changes. That judgment feels ordinary. For Immanuel Kant, it poses a difficult question: what must be in place for successive perceptions to count as experience of an object, rather than simply a succession of impressions?

The Critique of Pure Reason investigates the conditions and limits of human knowledge. Its first edition appeared in 1781; a second edition followed in 1787. The references here identify sections in the work, using the Meiklejohn translation linked throughout. The aim is to follow the central argument while keeping its ambitious conclusions distinct from the examples used to explain them. Primary text.

Kant's answer gives the knowing subject an active role. Experience requires something received through sensibility and something contributed by our capacity to think. The claim is stronger than the observation that people interpret things differently. Kant argues that objects of possible human experience must conform to certain conditions of our cognition. Those conditions make objective knowledge possible while limiting what that knowledge can establish.