As what Falzon postulated in his article on Descartes and Dualism, the author states that 'the dualist view of human beings means that it is possible for the mind to exist separately from the body (2002, p. 62)' but the persona is still that same person despite residing in another physical being. Thus, John Malkovich's mind may be transferred to Craig's body but then it is the personality of Malkovich that now resides in a different physical form. Schwartz used the memory of Malkovich to live a life he never had -- or even wanted as his old self and finds fulfillment in being John Malkovich. Although Descartes postulated that 'we had "clear and distinct" perception that the self was distinct from the body (Blackburn 1999, p. 122),' several arguments still come to mind and various philosophers and thinkers throughout the ages have endeavored to answer the dualist concept -- some of their arguments are valid and similar whilst others leave more questions on the nature of human being. The application and search for the answer to the dual nature of humankind will always be alive and active. It makes for a good topic of discussion amongst various thinkers and provide an interesting subject matter and genre for films. There may be no right or wrong answer on the dualist...

The film Being John Malkovich has all the ingredients of the arguments and counterarguments of the dualist nature of humankind but it served to answer the question though that if another person's memory is utilize by someone else, then the memory that is more pronounced takes precedence despite having a dual personality thereto. As what the audience have seen with Schwartz, he may have maintained his physical being but for several months he was Malkovich through and through.
Bibliography:

Jonze, S (dir) 1999, Being John Malkovich (film), Malkovich Films, United States.

Blackburn, S 1999. 'The Self' in Think, Oxford University Press, Oxford, pp. 120 -- 148.

Falzon, C 2002, 'Descartes and Dualism' in Philosophy goes to the movies, Routledge, London, pp. 60 -- 68.

Kerruish, E 2011, SOC10399: Philosophy on screen: Film and television, Southern Cross University, East Lismore.

Litch, M 2002, 'Personal Identity' in Philosophy through film, Routledge, New York, pp. 67 -- 86.

Witchalls, C 2007, 'Brain-bending numbers: Lab comes…