 Hurley discusses more aspects of the unity of consciousness than partial unity. She argues, for example, that there is a normative dimension to unified consciousness—conscious states have to cohere semantically for unified consciousness to result (we will return to this issue in  Section 7.3).  She discusses most of the kinds of breakdown phenomena that we considered earlier, exploring the implications of a wide range of ‘experiments of nature’ and laboratory experiments for the presence or absence of unified consciousness. In particular, she considers acallosal people (people born without a corpus callosum). Even though the corpus callosum, when present, is the chief channel of communication between the hemispheres, acallosal people show all the behavioural signs of having fully unified consciousness. If so, then the neurological and behavioural basis of unified consciousness would be very different in different people. (We will return to this last topic in  Section 8.)