  Absent such a model, factual or descriptive errors are all too likely. For example, claims about the unintelligibility of the link between experienced red and any possible neural substrate of such an experience sometimes treat the relevant color quale as a simple and sui generis property (Levine 1983), but phenomenal redness in fact exists within a complex color space with multiple systematic dimensions and similarity relations (Hardin 1992). Understanding the specific color quale relative to that larger relational structure not only gives us a better descriptive grasp of its qualitative nature, it may also provide some “hooks” to which one might attach intelligible psycho-physical links.