 To answer this question, we need to return to Locke’s famous discussion of personal identity, in which the notion of an animal was central…Locke exercised great care in specifying the different ideas for which the words ‘animal’ and ‘person’ stood. A reasonable conjecture, or proposal, we suggest, is that Locke’s treatment of these two terms and notions was so effective that it generated in people engaging with the problem the conviction that the notion of a person is the central one fixing the type of thing the problem is about, with the consequence that the notion of an animal was lost to sight. (2016: 3) 