Albert Einstein once said, “Reality is merely an illusion, albeit a very persistent one.” And he was not the first person to question the reality that way. Many philosophers have long held this view.
German philosopher Immanuel Kant drew a clear distinction between the forms that appear in the mind–what he called the phenomenon (a Greek word meaning “that which appears to be”)–and the world that gives rise to this perception, which he called the noumenon (meaning “that which is apprehended”). All we know, Kant insisted, is the phenomenon. The noumenon, the “thing-in-itself,” remains forever beyond our knowing.
But, what does this mean in the present context when we have far more understanding of both the outer world and our senses? Let us have a look.
Kalampedia 