Abstract. 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 then sketch an alternative account, which, while holding fast to the phenomenal compoundedness of the purple and to the impenetrability of component 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.Purple contains red and blue, orange contains red and yellow and (albeit more controversially) green contains yellow and blue. "Elementary colours" are colours such as yellow, blue, or red, which are not constituted by other colours but can themselves constitute other colours; "compound colours," by contrast, are colours such as green, purple, or orange, which are constituted by more elementary colours. A compound colour is a colour that consists of a mixture of two or more elementary colours different from itself. This paper aims to present and evaluate Brentano's theory of compound

L'idée de cet ouvrage tire en partie son origine d'un séminaire intitulé « Entre mathématiques, physiologie et phénoménologie : quel modèle pour la psychologie naissante en Allemagne au cours du XIX e -début XX e siècles ? » que nous avons organisé aux archives Husserl de Paris en 2011-2012. Nous sommes redevable à Jocelyn Benoist, qui dirigeait alors les archives Husserl, ainsi qu'à Michel Espagne, directeur de l'UMR 8547 Pays germaniques -Transferts culturels, pour nous avoir encouragé dans l'organisation du séminaire et pour avoir rendu possible le présent projet éditorial. Que soient ici remerciés le Centre national de recherche scientifique (CNRS), pour l'allocation fléchée dont l'éditeur a pu bénéficier entre 2010-2013 au sein des archives Husserl, ainsi que le Deutscher Akademischer Austauschdienst (DAAD) et l'Académie française, pour le financement actuel d'un projet de recherche en Allemagne.