Personal & Human Identity

John Locke, in his work “An Essay Concerning Human Understanding,” works to distinguish between the identities of man (which I will henceforth refer to as humans), immaterial souls (to be onward referred to as thinking substances), and persons. Through this, he then proceeds to portray personal identity as being irrelevant to identity as a human or a thinking substance, but instead reliant wholly on sameness of consciousness. In this essay, I will proceed to first explain Locke’s views of both human identity and thinking substances before moving next into personal identity and how it exists independently from the prior. Lastly, I will work to provide a personal rebuttal to Locke’s concept of personal identity through continuity of consciousness.

While Locke’s theory of understanding in general points toward a physicalist view of existence, his identity theory embraces a form of dualism. He claims that “matter, incogitative matter and motion, whatever changes it might produce of figure and bulk, could never produce thought,” but rectifies this by claiming that “the first Eternal thinking Being… should, if he pleased, give to certain systems of created senseless matter… some degrees of sense, perception, and thought.” This allows him to place dualism and physicalism on an equal footing in regard to the duality of mind and body by embracing a concept of property dualism, as while thinking substances may be immaterial it is also possible that they are material substances imbued with the property of thought. With this basis in place, Locke begins by explaining human identity as “nothing but a participation of the same continued life, by constantly fleeting particles of matter, in succession vitally united to the same organized body.” Through this, he is in base form applying a physical property to the body as it remains the same human as long as the same life is being continued by a material body which, while made of changing particle compositions, remains within a set organized system which is necessary for continuation of life as a human. There is then running parallel to this body the existence of a connected thinking substance, which embodies the mental property. This thinking substance, while facilitating consciousness, is in Locke’s view not consciousness itself but instead a separate entity. The continuity of this substance does not hold any necessity for either the identity of the body or of the person (to later be addressed), but instead functions as a sort of interchangeable intermediary between the two.

The consciousness, which exists external to both the body and this thinking substance that facilitates it, through its continuity is to Locke the source of personal identity. Locke claims that personal identity is “the sameness of a rational being.” Going from that definition, if we look at the example of the prince and the cobbler we see that the same body, or human identity, is ruled out as a determinate factor since while a prince’s thinking substance may be transferred to a cobbler’s body, and he may indeed recollect all of his thoughts, memories, experiences, and rationality as a prince, by the notion of human identity he would be for all purposes still simply the same cobbler as prior to the switch. It thus seems apparent that personal identity is not attributed to the body but instead to the consciousness, and that “as far as this consciousness can be extended backwards to any past action or thought, so far reaches the identity of that person.” Through this claim, Locke is saying that a person’s identity is linked to the ability of the same consciousness to recollect previous experiences or memories throughout the plane of time, or that personal identity relies on psychological continuity, and that if at any point person Y cannot recollect first-person the experiences of person X then they are not the same person. By saying this, Locke can then establish a way in which personal identity is maintained external to that of the body. This idea of psychological continuity is the major basis on which Locke attributes his view of personal identity. From here many would argue that it makes sense to say consciousness, and thus personal identity, could simply be part of the thinking substance and not actually a distinct thing existing on its own. However, Locke posits that the same form of flaw in attributing personal identity to the body also presents itself in regard to the thinking substance as one would first have to prove that personal identity cannot be maintained if the thinking substance is switched. Instead, Locke views the consciousness as a thing completely separate from, though facilitated by, the thinking substance. Being that he has shown what he sees to be a necessary distinction between the body, thinking substance, and consciousness, the psychological continuity of this consciousness, independent from any material or immaterial substance, can to Locke be the only requisite of personal identity. When studying Locke’s work more closely, however, there is an issue with these distinctions that keeps catching my attention.

When Locke defines a person, he defines it as “a thinking intelligent being, that has reason and reflection, and can consider itself as itself, the same thinking thing in different times and places; which it does only by that consciousness, which is inseparable from thinking, and as it seems essential to it: it being possible to perceive, without perceiving, that he does perceiving.” Locke states that to be a person, one must be a thinking being. This thinking being, then, perceives itself as being itself throughout time only through consciousness. This view of what a person is seems to necessitate the person being something capable of thinking, which then implies that the thinking substance is at the base of, or at the very least inseparable from, the person. Furthermore, it seems that Locke views consciousness as being inseparable from and more importantly essential to this thinking, which is a core part of the person. However, Locke proceeds from here to separate completely the identity of the person and consciousness from the thinking substance, saying that it is quite possible to remain the same person while being an entirely different thinking substance. This idea that the same person can remain even without the same thinking substance seems to go directly against Locke’s definition of what a person is to begin with, as it is very clear that Locke views the thinking substance as inseparable from personhood. To say that the thinking substance can be switched and identity maintained is not as simple as the idea of body switching as while the identity of the body has been ruled out previously as a possible contender for personal identity and thus has no value here, the thinking substance is within Locke’s own terminology essential to and seemingly conjoined to the idea of a person. To say that one maintains one’s identity as a person without maintaining all of what by definition makes one a person seems absurd. It seems to me, then, that in actuality the consciousness cannot truly be separated from the thinking substance and instead to say that identity relies on consciousness must be the equivalent of saying that it relies on the thinking substance as both of these elements are inseparable from Locke’s definition of what it means for one to be a person. With this being the case, Locke’s argument falls for his own previously mentioned objection as personal identity in the confines of his definition cannot survive the swapping of the thinking substance.

While Locke’s theory of personal identity looks incredibly solid on the surface, there arises to me a fundamental flaw in regard to how it functions alongside Locke’s view of personhood. It seems as though his own definition of what constitutes one being a person runs counter to what he views as how a person should be identified.

Work Referenced

Locke, John, and P H. Nidditch. An Essay Concerning Human Understanding. Oxford: Clarendon Press, 1979.



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Jamie Johnson

Jamie Johnson

they/he | I’m a materialist and Luciferian who studied design and philosophy! I also organize with the Party for Socialism and Liberation & ANSWER Coalition