Is Purple a Red and Blue Chessboard? Brentano on Colour Mixtures

Can we maintain that purple seems composed of red and blue without giving up the impenetrability of the red and blue parts that compose it? Brentano thinks we can. Purple, according to him, is a chessboard of red and blue tiles which, although individually too small to be perceived, are together indistinctly perceived within the purple. After a presentation of Brentano’s solution, we raise two objections to it. First, Brentano’s solution commits him to unperceivable intentional objects (the chessboard’s tiles). Second, his chessboard account fails in the end to explain the phenomenal spatial continuity of compound colours. We finally sketch an alternative account of compound colours, which, while holding fast to their phenomenal compoundedness and to the impenetrability of colours, avoids introducing inaccessible intentional objects and compromising on the continuity of the purple. According to our proposal, instead of being indistinctly perceived spatial parts of the purple, red and blue are distinctly perceived nonspatial parts of it.