George Berkeley may have been echoing Swift's irony when he linked his nationality, as an Irishman, with the limited scope of his ideas. However, his apparent diffidence about the metaphysical excursions of others did not prevent him from proposing, in his relative youth, a form of idealism that many of his contemporaries considered counter-intuitive and possibly irrational. The so-called immaterialism of the Principles and the Dialogues may still strike some readers today as bizarre, or even as symptomatic of psychiatric illness, because it appears to deny the reality of familiar objects of everyday experience. There is, therefore, a paradox at the core of what Berkeley presents as a ‘revolt from metaphysical notions to the plain dictates of nature and common sense’ (D, 172). On the one hand, he claims to defend common sense, not to speculate beyond the limits of sensory experience, and to provide a bulwark against scepticism. On the other hand, he seems to deny the reality of the familiar physical world, of houses, mountains and rivers, and even of the people with whom we discuss the merits of philosophical theories.