linguistic:paraphrasing, quality:corruption
Modern critiques

In the Western world, the popularity of idealism as a metaphysical view declined severely in the 20th century, especially in English language analytic philosophy. This was partly due to the criticisms of British philosophers like G. E. Moore and Bertrand Russell and also due to the critiques of the American "new realists" like E.B. Holt, Ralph Barton Perry and Roy Wood Sellars.

Moore famously critiqued idealism and defended realism in The Refutation of Idealism (1903), and A Defence of Common Sense (1925). In the Refutation, Moore argues that arguments for idealism most often rely on the premise that to be is to be perceived (esse est percipi), but that if this is true "how can we infer that anything whatever, let alone everything is an inseparable aspect of any experience?". Bertrand Russell 's popular 1912 book The Problems of Philosophy also contained a similar critique. Their main objection is that idealists falsely presuppose that the mind's relation to any object is a necessary condition for the existence of the object. Russell thinks this fallacy fails to make "the distinction between act and object in our apprehending of things" (1912). Guyer et al. write that the success of these arguments might be controversial and that "the charge that they simply conflate knowledge and object hardly seems to do justice to the elaborate arguments of the late nineteenth-century idealists." It also relies on a realist epistemology in which knowledge stands "in an immediate relation to an independent individual object".

Regarding positive arguments, Moore's most famous argument for the existence of external matter (found in Proof of an External World, 1939) was an epistemological argument from common sense facts, sometimes known as " Here is one hand ". Idealism was also more recently critiqued in the works of Australian philosopher David Stove, and by Alan Musgrave, and John Searle.