The HIT model explains the existence of semantic category-specific deficits by assuming that sensory knowledge is crucially important in processing living things, while functional knowledge is crucially important in processing nonliving things – the sensory/functional assumption. Here we argue that the sensory/functional assumption as implemented in HIT is neither theoretically nor empirically grounded and that, in any case, there is neuropsychological evidence which invalidates this assumption, thereby undermining the HIT model as a whole.