PHL 550 Study Guide - Final Guide: Sharpening
10 Apr 2017
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Document Summary
The debates surrounding the problem of personal identity concern identity over time- that is, identity from one time to another. To understand this problem correctly, we need to be clear about the idea of numerical sameness, which is best understood by contrast with qualitative sameness. Two things are qualitatively the same, or qualitatively identical, when and only when they have the same characteristics. I am not the same age or the same weight, and my hair is not the same colour, as the person who bore my name 30 years ago. Because some of my characteristics or qualities have changed, i am not qualitatively identical with my earlier self. Identical twins can be qualitatively identical and still be two persons, but they cannot be numerically identical and still be two. Definition: two things are qualitatively the same, or qualitatively identical, when they have the same characteristics.
