Tuesday, June 3, 2014

A Mind Divided Against Itself – Cartesian Soul Theory and Brain Splitting?

Jeff McMahan in his book The Ethics of Killing – Problems at the Margins of Life, examines several accounts of personal identity – what we really are. Among those examined is the theory that we are souls.  McMahan finds several problems with soul theory, both hylomorphic soul theory and Cartesian soul theory.  

This paper, however, is solely concerned with his treatment of Cartesian soul theory, which will be referred to as soul theory for the remainder of this paper.  I will attempt to show why McMahan’s objections to soul theory do not hit the mark.  First, I will examine whether his contention that studies showing divided consciousness in patients whose corpus callosum has been surgically split, spells the end for Cartesian dualism.  Second, I will show that McMahan is somewhat less convinced that such patients have divided consciousness when this example becomes an issue for his theory of personal identity.  Finally, I will review his thought experiment concerning the splitting of one’s cerebral hemisphere into two parts and whether the insertion of these hemispheres into two different bodies can be reconciled with soul theory.

Click on this link to read the full  a paper.