Subjective idealism
Subjective idealism made its mark in Europe in the 18th-century writings of George Berkeley, who argued that the idea of mind-independent reality is incoherent, concluding that the world consists of the minds of humans and of God.
Immanuel Kant responded by rejecting Berkeley's immaterialism and replacing it with transcendental idealism, which views the mind-independent world as existent but incognizable in itself.
Since Kant, true immaterialism has remained a rarity, but is survived by partly overlapping movements such as phenomenalism, subjectivism, and perspectivism.
Hegel rejected Kant's immaterialism, demeaning it to a "reduction of the facts of consciousness to a purely personal world.
"[1] Thinkers such as Plato, Plotinus and Augustine of Hippo anticipated idealism's immaterialistic thesis with their views of the inferior or derivative reality of matter.
Plato helped anticipate these ideas by creating an analogy about people living in a cave which explained his point of view.
[2] This sets up the idea of Berkley's theory of immaterialism because it shows how people can be exposed to the same world but still see things differently.
Indeed, Plato rationalistically condemned sense-experience, whereas subjective idealism presupposed empiricism and the irreducible reality of sense data.
A more subjectivist methodology could be found in the Pyrrhonists' emphasis on the world of appearance, but their skepticism precluded the drawing of any ontological conclusions from the epistemic primacy of phenomena.
The first mature articulations of idealism arise in Yogacarin thinkers such as the 7th-century epistemologist Dharmakīrti, who identified ultimate reality with sense-perception.
The most famous proponent of subjective idealism in the Western world was the 18th-century Irish philosopher George Berkeley, whose popularity eclipsed his contemporary and fellow Anglican philosopher Arthur Collier - who perhaps preceded him in a refutation of material existence, or as he says a "denial of an external world" - although Berkeley's term for his theory was immaterialism.
"[9] Newton's laws of physics say that all movement comes from the inverse change in another motion, and materialists believe that what humans do is fundamentally move their parts.
Aristotle held that while visual perception suffered a compromised authenticity because it passed through the diaphanous liquid of the inner eye before being observed, sound and the experience of hearing were not thus similarly diluted.
Alan Musgrave[11] argues that conceptual idealists compound their mistakes with use/mention confusions; and proliferation of hyphenated entities such as "thing-in-itself" (Immanuel Kant), "things-as-interacted-by-us" (Arthur Fine), "table-of-commonsense" and "table-of-physics" (Arthur Eddington) which are "warning signs" for conceptual idealism according to Musgrave because they allegedly do not exist but only highlight the numerous ways in which people come to know the world.
[citation needed] A parable of subjective idealism can be found in Jorge Luis Borges' short story Tlön, Uqbar, Orbis Tertius, which specifically mentions Berkeley.
