In philosophy, condition of possibility (German: Bedingungen der Möglichkeit) is a concept made popular by the German philosopher Immanuel Kant, and is an important part of his philosophy.
It was believed that the perceptions ought to be overcome to grasp the thing-in-itself, the essential essence, also known as Plato's allegory of the cave.
Immanuel Kant does just this in the Transcendental Aesthetic, when he examines the necessary conditions for the synthetic a priori cognition of mathematics.
But Kant was a transitional thinker[clarification needed], so he still maintains the phenomenon/noumenon dichotomy, but what he did achieve was to render Noumena as unknowable and irrelevant.
[1] Foucault would come to adapt it in a historical sense through the concept of "episteme": what I am attempting to bring to light is the epistemological field, the épistémè in which knowledge, envisaged apart from all criteria having reference to its rational value or to its objective forms, grounds its positivity and thereby manifests a history which is not that of its growing perfection, but rather that of its conditions of possibility; in this account, what should appear are those configurations within the space of knowledge which have given rise to the diverse forms of empirical science.