A Reductionist Account of Personal Identity
Reductionist Account of Personal Identity
References
Rene Descartes, Meditations on First Philosophy. New York: Classic Books America, 2009.
John Locke, An Essay concerning Human Understanding. Indianapolis: Hackett, 1996.
Thomas Nagel, The View from Nowhere. Oxford: Oxford University Press, 1986.
Derek Parfit, "Experiences, Subjects and Conceptual Schemes," Philosophical Topics, 26, 1/2 (1999): 217-270.
Derek Parfit, "Is Personal Identity What Matters?" The Ammonius Foundation. http://www.ammonius.org/assets/pdfs/ammoniusfinal.pdf (accessed December 31, 2007).
Derek Parfit, Reasons and Persons. Oxford: Oxford University Press, 1984.
Derek Parfit, "The Unimportance of Identity," in Identity, edited by H. Harris, 13-46. Oxford: Oxford University Press, 1995.
W.V. Quine, "Identity and Individuation," The Journal of Philosophy, 69 (1972): 488-497.
Sydney Shoemaker, "Persons and Their Pasts," American Philosophical Quarterly, 7 (1970): 269-285.
Bernard Williams, Problems of the Self. Cambridge, UK: Cambridge University Press, 1973.
Ludwig Wittgenstein, Zettel. Oxford: Blackwell, 1967.
Overview
Philosophers have long debated the nature of persons and the conditions for numerical identity over time. This section explores the distinction between numerical and qualitative identity, the implications for personal identity, and the reductionist framework addressing these concepts.
Numerical vs. Qualitative Identity
Numerical Identity: Refers to whether two entities are the same individual.
Example: Two identical chairs at a kitchen table are qualitatively identical (same appearance, material) but not numerically identical (they are two separate objects).
Qualitative Identity: Refers to the qualities or characteristics of an object that may change over time.
Example: A single chair that has been repainted is numerically the same chair but qualitatively different after the change.
The concept can be applied to personal identity, for example, when a relative observes psychological changes but acknowledges the same individual remains intact.
Philosophical Debates on Identity
Philosophers debate whether a person who has undergone complete memory loss and radical character change can still be considered numerically the same as their former self.
Derek Parfit argues that, under these circumstances, one would face a numerically different entity, as they lack psychological continuity.
Conversely, Bernard Williams contends that numerical identity is maintained as long as there is physical continuity.
The crux of the debate centers around the definition of “person” and how this concept should be understood and applied.
John Locke's Forensic Concept of Person
Locke asserts the concept of ‘person’ is forensic, derived from the Latin term ‘forum’ meaning public.
He contends that meaning is determined by usage consistent with common beliefs, attitudes, and practices.
In legal contexts, one cannot be guilty of a crime without recollecting committing it—memory is a prerequisite for responsibility.
There are philosophical disagreements regarding whether ‘person’ conveys accurate meaning through common use. Parfit critiques this traditional view, asserting philosophers must evaluate common usage for inconsistencies and engage in a more rigorous discourse on the implications of identity.
Reductionism vs. Nonreductionism
Philosophers take two main approaches regarding personal identity: reductionist and nonreductionist.
Reductionist Approach
Constitutive Reductionism: Argues that persons exist as entities but are fully constituted by their physical and psychological continuities. They are not separate entities existing over and above these continuities.
This view holds that experiences associated with persons can be described without necessarily attributing them to an independent identity.
Analogy: Sydney Shoemaker states the relationship is akin to that of a statue and its clay: entirely constituted by clay but not identical to it despite being inseparable.
Nonreductionist Approach
Metaphysical Nonreductionism: Holds that persons are separately existing entities. For instance, an individual may identify a person with their soul, which does not depend on any combination of further entities.
Philosophers like those who believe in the transmigration of souls argue that they could be numerically identical to a past person despite differences in body, character, and memory.
Further Distinctions within Reductionism
Within reductionism, scholars like Bernard Williams and Thomas Nagel argue for physical continuity, while Parfit and Shoemaker assert that psychological continuity is paramount.
Parfit's argument suggests one must choose between reductive and nonreductive frameworks, indicating the absence of substantive evidence for nonreductionism and explaining psychological continuity without presupposing identity.
Key Premises and Arguments for Reductionism
P1: The fundamental distinction for persons lies between nonreductionist and reductionist views, as noted by Parfit.
P2: Nonreductionists view persons as distinct from their bodies and experiences.
P3: Reductionists claim persons are indeed distinct but not separate entities.
P4: Reductionism is valid if psychological continuity occurs without presupposing a unified identity across experiences.
Psychological Continuity and Quasi-Memories
Definition of quasi-memories: An accurate quasi-memory of a past experience involves recalling an event that one did not directly experience but whose memory is causally linked to that past experience.
If the continuity of quasi-memories suggests a relation among different persons, such phenomena may indicate psychological continuity can be shared rather than presuming individual identity, leading to complexities in defining personal identity.
Summary of Arguments Supporting Reductionism
Parfit contends that if we lack direct evidence for persons existing independently, we ought to dismiss the belief in separate entities. The argument emphasizes that (P10) there is no awareness of a sustained separately existing subject and that evidence for psychological continuity is not reliant on continuity of a nonmaterial essence but on the existence of the brain and body and psychological processes.
Thought Experiments and Philosophical Critique
Thought experiments are employed to investigate intuitions about identity, but their legitimacy has been challenged by philosophers like Quine and Wittgenstein, suggesting that our understanding of identity cannot be extrapolated from alternate worlds.
Conclusion: The reductionist view posits that an individual's identity arises from psychological continuity rather than material existence.
Split-Case Arguments about Personal Identity
Discusses the dilemma presented by split cases, highlighting issues with identity criteria based on shared mental properties or physical continuity.
The concept of a brain being divided and implanted in other bodies illustrates complications in defining personal identity without positing a distinctive entity, leading thinkers like Richard Swinburne to argue for an immaterial aspect (soul) as necessary for personal identity.
The Ship of Theseus
Explores identity through the analogy of Theseus's ship, where ongoing repairs replace components until the entire ship is new. This complicates identity continuity, leading to discussions of whether two restored ships could coexist as the same entity.
Epicurus's Argument on Death
Examines views of death as non-threatening in the pursuit of achieving tranquility or ataraxia. Epicurus argues that death is irrelevant to the living, prompting philosophical discussions on the nature of existence and fear.
Fatalism
Discusses fatalism as the doctrine that all events are predetermined, showcasing how linguistic and logical structures can wrongly support fatalist assertions. The implications of fatalism challenge agency and decision-making.
Sartre’s Argument for Freedom
Contrasts Sartre's views on freedom, emphasizing the necessity of individual interpretation of existence over determinism, proposing that actions arise from consciousness's ability to define meaning.