Keith Allen

Ralph Cudworth (1617–1688) is a member of the group of philosophers and theologians commonly called ‘the Cambridge Platonists’. Although not part of the canon of great early modern philosophers, Cudworth’s work is of more than merely passing interest. Cudworth was an influential philosopher in the early modern period both for his criticisms of contemporaries like Hobbes, Descartes, and Spinoza, and for his own distinctive philosophical views. This entry focusses on Cudworth’s views on mind and body, considering both his criticisms of contemporaries’ theories of mind and body, and outlining his alternative form of dualism in which plastic nature plays a central role.

Inter-species variation in colour perception poses a serious problem for the view that colours are mind-independent properties. Given that colour perception varies so drastically across species, which species perceives colours as they really are? In this paper, I argue that all do. Specifically, I argue that members of different species perceive properties that are determinates of different, mutually compatible, determinables. This is an instance of a general selectionist strategy for dealing with cases of perceptual variation. According to selectionist views, objects simultaneously instantiate a plurality of colours, all of them genuinely mind-independent, and subjects select from amongst this plurality which colours they perceive. I contrast selectionist views with relationalist views that deny the mind-independence of colour, and consider some general objections to this strategy.

Colours appear to instantiate a number of structural properties: for instance, they stand in distinctive relations of similarity and difference, and admit of a fundamental distinction into unique and binary. Accounting for these structural properties is often taken to present a serious problem for physicalist theories of colour. This paper argues that a prominent attempt by Byrne and Hilbert to account for the structural properties of the colours, consistent with the claim that colours are types of surface spectral reflectance, is unsuccessful. Instead, it is suggested that a better account of the structural properties of the colours is provided by a form of non-reductive physicalism about colour: a naïve realist theory of colour, according to which colours are superficial mind-independent properties.

Locke Defines Knowledge at the beginning of Book IV of the Essay concerning Human Understanding as “the perception of the connexion and agreement, or disagreement and repugnancy of any of our Ideas” (E IV.i.2).1 So defined, knowledge varies along two dimensions. On the one hand, there are four “sorts” of knowledge: of identity or diversity; relation; co-existence or necessary connection; and real existence. On the other hand, there are three “degrees” of knowledge: intuitive knowledge, which consists in the “immediate” perception of agreement or disagreement between ideas (E IV.ii.1); demonstrative knowledge, which consists in the perception of agreement or disagreement by way of intermediate (or intervening)..

This paper presents an ‘over-representational’ account of blurred visual experiences. The basic idea is that blurred experiences provide too much, inconsistent, information about objects’ spatial boundaries, by representing them as simultaneously located at multiple locations. This account attempts to avoid problems with alternative accounts of blurred experience, according to which blur is a property of a visual field, a way of perceiving, a form of mis-representation, and a form of under-representation.