According to Gärdenfors, the formal property of convexity in a conceptual space can serve as a criterion of projectibility. This theory is here criticized on two grounds: 1) Gärdenfors is inconsistent when applying the criterion to the troublesome Goodman predicate ’grue’; 2) dispositional predicates are typically non-convex and yet projectible. Projectibility is suggested to be neither a matter of logic nor one of symbolism.