Indeterminacy: On the Fission – Xinyi Song

INDETERMINACY: ON THE FISSION

By Xinyi Song

In Reasons and Persons, Derek Parfit comes up with the thought experiment of “fission” to support his argument that personal identity does not matter (1986). In his science-fictional setting, two cerebral hemispheres of one person can be transplanted into two heads thus bringing about the dilemma of personal identity. After examining a brief reconstruction of Parfit’s argument, another possible explanation of this case, i.e. the “four- dimensionalism” view, is proposed for comparison. Through this approach, I come to find some difficulties in the assessment and eventually suggest that before finding any genuine proof other than common-sense intuition, it might be reasonable to suspend judgement between the argument of Parfit and that of Sider.

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