Immanuel Kant'
s epistemological philosophical
system which holds that
space and time are not properties of independent
real things in themselves, but are rather a priori intuitions possessed by our minds, and everything we perceive is subject to this
space and time intuition. However, as opposed to
George Berkeley's subjective idealism which holds that nothing exists
outside the mind, Kant's transcendental idealism accepts the existence of external objects independent of our mind but distinguishes between noumena (things-in-themselves as they actually are) and phenomena (things as we perceive them), we can only Intuit the phenomena (or the appearance of the object) from the noumena (which we can never directly perceive). Thus Kant acknowledges that while we can never know the noumena, the phenomena sufficiently conform to our concepts of them and that in order to make sense of the empirical world, we must presuppose transcendentally a consciousness that unites intuitions under concepts.
