Idealism
Reality is fundamentally mental or spiritual in nature.
Overview
Idealists argue that what we call 'reality' is ultimately constituted by mind, consciousness, or spirit — not by matter existing independently of perception. This ranges from Berkeley's claim that physical objects are collections of sensory ideas sustained by God's mind, to Hegel's grand vision of all reality as the progressive self-realization of Absolute Spirit through history. Idealism takes seriously the fact that we never experience a world independent of consciousness.
Origins
Philosophical idealism has ancient roots in Plato, but it became a dominant force in the 18th-19th centuries. Kant argued that the mind structures all experience (transcendental idealism). Hegel radicalized this into absolute idealism — the claim that reality itself is rational and spiritual. German idealism was among the most ambitious philosophical movements since ancient Greece and shaped Marx, existentialism, and much of later thought.
Key Thinkers (5)
Gottfried Wilhelm Leibniz
1646 CE – 1716 CE
This is the best of all possible worlds; reality consists of infinite simple substances called monads.
George Berkeley
1685 CE – 1753 CE
To be is to be perceived: matter doesn't exist independently of minds.
Immanuel Kant
1724 CE – 1804 CE
The mind actively structures experience; morality is grounded in universal rational duty.
G.W.F. Hegel
1770 CE – 1831 CE
Reality is the self-development of Absolute Spirit through dialectical progression.
Arthur Schopenhauer
1788 CE – 1860 CE
The world is driven by a blind, purposeless Will; salvation lies in aesthetic contemplation and compassion.