國立臺灣大學哲學系Department of Philosophy , National Taiwan University黃懿梅Huang, Y.M.Y.M.Huang2017-09-082018-05-292017-09-082018-05-291997-06http://ntur.lib.ntu.edu.tw//handle/246246/281922D. Lewis asserts that ‘We can agree with Parfit...that what matters in questions of personal identity is mental continuity or connectedness...At same time we can consistently agree with common sense...that what matters in questions of personal identity is identity’, but D. Parfit believes that this cannot be done. The aim of this paper is to re-examine whether Lewis's thesis, ‘the I-relation and the R-relation coincide’, had been justified. In sections 2 and 3, I summarized Lewi’s and Parfit's arguments separately. And the related cohabitationist's theory is introduced in section 4. After the discussion in section 5, I argue that Lewis's thesis cannot be justified.journal article