 Holkot also differed with Ockham about the nature of abstractive cognition. He argued in favor of retaining species as part of natural and cognitive processes. In De stellis he refers to the sun propagating the natural species of light through the medium of the air. He did not consider the species operative in cognition to be such natural species, however. The term ‘species’ when used to refer to the whiteness in one external object and to the whiteness in another could be called univocal, having the same meaning in each case, but the term ‘species’ used to refer to the whiteness in an object as a quality and to the whiteness representing the object in the intellect was equivocal. The intellectual species is only a likeness of the thing in the sense of representing it (like a statue of Hercules in relation to Hercules), and we experience it in ourselves as it enables us to think about an external object in the absence of that object. Holkot was not much concerned whether such “spiritual qualities” were called “species,” “idols,” “images,” or “exemplars” as long as they were understood to serve as representatives of things or even “knowledge habits” and not as the natural qualities that exist in extramental reality. Holkot’s opponent was not Ockham, here, however, but his Dominican contemporary William Crathorn, who had argued for the view that natural and cognitive species were the same in kind. Holkot ridiculed Crathorn’s position at length in the Sex articuli, on the grounds that if Crathorn were right, our minds would become white or black, hot or cold, depending on what we were thinking about. Crathorn was arguing in line with a long tradition stretching back to Roger Bacon. Holkot’s sharp disjunction between natural and spiritual “likenesses,” natural and spiritual qualities, went beyond the traditional distinction between sensible and intelligible species and seems to show the effects of the Ockhamist critique, even while he retained remnants of the Aristotelian vocabulary.