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Personal Identity

Clinical Observations

(Text as at 18/08/2009 20:39:50)

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

Clinical observation may be a better guide that thought experiments¹ as test cases for our theories of personal identity, because at least we know they represent a real possibility. However, we still have the trouble of the correct interpretation of the clinical data. 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.

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? Note here that “patient” is a Phase Sortal⁴ of the Ultimate Sortal⁵ “human being⁶”. 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 kind⁷ to the one thing. The logic⁸ 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 Dicephalus⁹.