A theory propounded by Greek philosopher Plato (circa 429-347 BCE) which states that all knowledge must originate in a hypothetical existence before birth, wherein humans attain knowledge of the true forms or essences of the material world. This knowledge is accessed after birth with the mental processes of recollection or reminiscence. Plato posited that this hypothetical existence was the only way for a human to have knowledge of certain concepts like perfect equality, which cannot be gleaned from experience. See also: Platonic idealism, theory of forms.
REMINISCENCE THEORY OF KNOWLEDGE: "Plato expounded many theories, one of which was the Reminiscence Theory of Knowledge."