Materialism typically contrasts with dualism, phenomenalism, idealism, vitalism and dual-aspect monism. Scholarly interpretations of Vasubandhu's philosophy vary widely, and include phenomenalism, neutral monism and realist phenomenology. Irrealism was initially motivated by the debate between phenomenalism and physicalism in epistemology. Roderick Chisholm criticized the logical positivist version of phenomenalism in 1948. Ernst Mach's positivism and phenomenalism were a major influence. Realist conceptions include phenomenalism and direct and indirect realism. In 2008, he put forward a thesis called phenomenalistic idealism, which combines phenomenalism and idealism. Plato ascribes to Protagoras an early form of what John Wild categorized as phenomenalism. This view has similarities with phenomenalism. See for comparison Sensualism, to which phenomenalism is closely related. Phenomenalism is a radical form of empiricism. However, phenomenalism is based on mental operations. By the 20th century, views similar to Berkeley's were called phenomenalism. The former accounts for Renouvier's acceptance of Kant's phenomenalism, combined with rejection of the "thing-in-itself". He argues for a sophisticated sense-datum account, although he rejects phenomenalism.