Matter and Time as Truisms: A Critical Evaluation of G. E. Moore's Common Sense and Refutation of Idealism

George Edward Moore’s A Defence of Common Sense and The Refutation of Idealism constitute a decisive challenge to early twentieth-century idealism, particularly the view that reality is fundamentally mental. Idealist positions such as George Berkeley’s principle esse est percipi and J. M. E. McTaggart’s denial of the reality of time attempt to undermine the independence of the external world and ordinary temporal experience. Against these views, Moore advances a common sense realism grounded in what he terms “truisms”: propositions known with certainty and presupposed in everyday life. This paper critically evaluates Moore’s response to idealism by examining his defense of material objects and temporal reality as facts known independently of perception. It argues that Moore’s appeal to common sense not only exposes the conceptual excesses of idealism but also reaffirms the philosophical legitimacy of ordinary knowledge as a foundation for metaphysical inquiry.