Editorial for Minds and Machines Special Issue on Philosophy of Colour

Abstract

This special issue of Minds and Machines presents new work in the philosophy of colour. While this research is informed by recent findings in the colour sciences, it grapples with one of the perennial disputes in metaphysics: what kinds of properties are the colours and where, if anywhere, are they instantiated? The dispute typically takes the form of a weighing of the costs and benefits of one of the core theories in colour ontology. In this editorial I will give a brief overview of background debates, summarise the main points of the articles assembled here, and comment on some of their interconnected themes. Let’s first look back on the recent history of the colour debate. Hardin (1988) marshalled results from colour psychophysics to argue that chromatic properties are in fact never instantiated and should be eliminated from our ontological inventory. Almost simultaneously Hilbert (1987) proposed that colours are actually spectral surface reflectances (SSR’s)—physical properties as real as any other (cf. Matthen 1988; Byrne and Hilbert 2003). Much of the literature of that time was taken up with the dialectic between these two views. In comparison with the debate of 20 years ago the papers showcased here reflect the centrality of colour relationism to current discussions. Relationism, can be thought of as a middle path between Hardin’s eliminativism and Hilbert’s physicalism. It is the idea that colours are real (instantiated) properties but unlike ordinary physical properties they are in some sense perceiver-related (Thompson 1995; Cohen 2004, 2009). Why should one be a relationist about colour? A standard argument comes from phenomena of perceptual variation. An extreme example of colour visual variation gripped the world’s attention back in February this year. As Gegenfurtner et al.