Berkeley’s Anti-Abstractionism As a Grounds for the Likeness Principle
Peter West (Trinity College, Dublin)

part of: Perception, Knowledge, and Assimilation
June 12, 2017, 2:30pm - 3:30pm
Department of Philosophy, History, Culture and Art Studies, University of Helsinki

Auditorium IV in the main building of the University of Helsinki (Päärakennus)
Fabianinkatu 33

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  • European Research Council Project "Rationality in Perception: Transformations of Mind and Cognition 1250-1550" (Helsinki)
  • Research Programme "Representation and Reality. Historical and Contemporary Perspectives on the Aristotelian Tradition" (Gothenburg)


In §8 of the Principles of Human Knowledge Berkeley clearly and confidently states that, “an idea can be like nothing but an idea.” This claim, commonly referred to as the ‘Likeness Principle,’ is traditionally viewed as a problematic one. It is strikingly brief: Berkeley presents the view held by representationalists, uses the Likeness Principle to combat that view and then attempts to justify this move all within this short section. There is also a further concern about the Likeness Principle, in that it contradicts Berkeley’s account of successful argument and persuasive strategy. By introducing what appears to be an ungrounded claim in section 8, Berkeley undermines his own strategy of gradually ‘rooting out’ false persuasions.

I argue that it is Berkeley’s rejection of abstract ideas, in the Introduction to the Principles, which grounds the ‘Likeness Principle’. In denying that it is possible for the mind to conceive of abstract ideas (ideas which purport to represent something which is indeterminate), Berkeley establishes that the only ideas that the mind can conceive of are determinate. This means that the only ideas that the mind can conceive of as alike are, likewise, determinate. For Berkeley, the nature and ontology of ideas is determined by the mind’s capacity to conceive. Thus, if the only thing the mind can conceive of as being like a determinate idea is another determinate idea, then all that can be like an idea is another idea.

This reading explains Berkeley’s seemingly brief treatment of the Likeness Principle, is consistent with his argumentative strategy, and has the added advantage of tying together two of the most significant features of Berkeley’s immaterialism. In placing this argument in the Introduction, I shall argue, Berkeley was perhaps too careful in disclosing and rooting out his opponents’ false persuasions.

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