Theo Todman's Web Page - Notes Pages

Personal Identity

Clinical Observations

(Text as at 18/08/2009 21:11:31)

*** THIS IS NOT THE LATEST VERSION OF THIS NOTE ***

Clinical observations may be a better guides than thought experiments¹ as test cases for our theories of personal identity, because at least we know they represent a real possibility. One of the main objections to TEs is that they are underspecified and confused. However, even with actual clinical observation, we still have the trouble of the correct interpretation of the clinical data, which affects the conclusions we can draw from it. See "Wegner (Daniel) - The Illusion of Conscious Will - Preface" and "Wegner (Daniel) - The Illusion of Conscious Will" for the sort of controversy that arises in these circumstances. [I need to explain this a bit further!]

Examples of relevant clinical cases are commissurotomy² patients and those with multiple personality disorder³ (MPD). Is a commissurotomy or MPD patient “home to” one or two people?

I argue elsewhere [where⁴?] that PATIENT – like PERSON – is a Phase⁵ Sortal of the Ultimate Sortal⁶ HUMAN BEING⁷. One human being can simultaneously be multiple patients (dental and chiropody, for instance), or a multiply-enrolled student. Does this situation mirror those of our more seriously damaged human beings?

One thing can’t be two things (in the sense of “be identical to”), even if the two things are of a different kind⁸ to the one thing. The logic⁹ of identity would force the “two” things to be identical. But the Phase Sortal approach doesn’t force this violation of logic, so could a human being with split personality literally be the home of two, or three, or seven different thinking beings? (Wilkes). I’m inclined to say “yes”, but what impact does that have on animalism?

See also Dicephalus¹⁰.