Platonism is a philosophical system that derives its ultimate inspiration from Plato. It is the view that there exist abstract objects, which are objects that do not exist in space or time and are entirely non-physical and non-mental. Platonism affirms the existence of abstract objects, which are asserted to exist in a third realm distinct from both the sensible external world and from the internal world of consciousness. This can apply to properties, types, propositions, meanings, numbers, sets, truth values, and so on. Platonism sees these abstract objects as the causes of the existence of everything in the universe and as giving value and meaning to its contents in general and the life of its inhabitants in particular.
Platonism is not a monolithic system, and contemporary Platonists do not necessarily accept all doctrines of Plato. In a narrower sense, the term might indicate the doctrine of Platonic realism, a form of mysticism. The central concept of Platonism is the distinction between the reality which is perceptible but unintelligible, associated with the flux of Heraclitus and studied by the likes of science, and the reality which is imperceptible but intelligible, associated with the unchanging being of Parmenides and studied by the likes of mathematics.
Platonism had a profound effect on Western thought, and it is still an active area of research in contemporary philosophy.
