Berkeley's anti-abstractionism has been most öfter presented as a theory motivated by and about Locke's inconsistent idea of a triangle. His purpose, it is assumed, was to show that Locke gave the wrong account of how a general term like "triangle" is used to stand for triangles. Berkeley's theory, so interpreted, as part of a controversy with Locke, has been much discussed; but throughout this discussion, a certain anomaly has remained. Berkeley's attack on abstract ideas was written as the introduction to his Treatise concerning the Principles of Human Knowledge and he regarded his anti-abstractionism as the cornerstone for all other doctrines to be found there. No account of Berkeley's anti-abstractionism can be adequate, therefore, which fails to explain its importance to Berkeley in his exposition of his theory, but the prevailing accounts that concentrate on the general idea of a triangle fail to provide such an explanation. Instead, commentators who remark on the lack of clear connection between Berkeley's imma-terialism and the theory of abstract ideas they discuss, tend to see this as a problem for Berkeley, claiming that he exaggerated the importance of his attack on abstraction.¹ It is my view that Berkeley's antiabstractionism can be shown to have the central role that he claims for it, but that this requires downplaying Locke's triangle in order to focus on other aspects of Berkeley's argument about abstraction.