The self can be variously conceived of as who we are at our core, who we aspire to become, or an idea we act in alignment with. But how can one believe in the unchanging nature of the self, especially in the face of constant physical and psychological change? Philosophers and psychologists alike have offered explanations, and in this paper my intention is to advocate for the notion that there is no true self, with reference to the lens of psychological continuity.

The view of personal identity existing through psychological continuity is held by philosophers such as John Locke, who says that if there is a chain of overlapping mental states, like memories or desires that can connect the person that we are now to the person we shall be in the future, then despite all changes, our self will remain the same. This is often referred to as the memory criterion, which can seem to imply that were you to suddenly lapse into a vegetative state that was irreversible, you would cease to exist. The being that remains after could not possibly be you due to its lack of memories of being you. This raises the question of persistence: what is necessary and sufficient for a past or future version of yourself to also have been the present version of yourself existing right now, namely to be psychologically continuous. 

It is often a theme in thought experiments, such as body swaps or teletransportation. Most find themselves naturally drawn to this theory, for if you were to imagine a scenario where your brain were transplanted into another body, taking with it your memories and other mental features, the person with your brain and another’s body would still consider itself to be you. Other than memory, which is to say a past or future version of yourself can still claim to be you if they can recollect a memory that matches an experience that version of yourself had, there is further speculation as to what exactly is the psychological relation responsible for this continuity.

These kinds of sci-fi style thought experiment also raise the problem of potentially suggesting that two persons in the future can be psychologically continuous with one person existing in present time: the two from one problem, referred to as fission, which psychological-continuity theorists have come up with two different solutions for…

The first, sometimes called the “multiple-occupancy view”, says that despite the fission remaining an event in your future, there are the two of you existing even now, in a manner of speaking. The person that we think of ourselves to be at any given time is in fact two different people, who are now exactly similar and occupy the same location, carry out the same actions and think the same thoughts. This view is usually found in conjunction with the general metaphysical claim of four-dimensionalism, the claim that people and other things with the ability to persist share the quality of being made up of temporal parts. These temporal parts converge and then separate again, sharing some spatial parts but not others. However, whether we really are composed of temporal parts is disputed. More specifically, it is said these temporal parts refer to parts of you that only exist within a certain period of time of your life, for every period of time of your life. The implications for being made up of temporal parts would again land us in the previous dilemma of having a vast array of possible selves that could be the singular true self we speak of. 

A more common proposal would be the claim that psychological continuity on its own is not sufficient for our persistence, and that past or future versions of ourselves can only be ourselves if they, and no other being but them, are psychologically continuous with us.  Called the non-branching view, this proposal results in the extraordinary consequence of, in a situation where your brain has been divided, you would survive if one half had been preserved, but ceased to exist if both had been. This view is largely to what we owe the fascination of the question of what matters when it comes to the constitution of our identities; as it consequently raises the question of which hemisphere you would want to be transferred, there is no evident reason as to why you would show a preference for one over the other. The majority would also much rather want to preserve both hemispheres of our brains, but in the lens of fission, this would be the same as to prefer death over continued existence. Fission cases threaten the claim that the psychological continuity view of the existence and persistence of the self is better than those of a more physiological stance. 

This segues to yet another objection to psychological continuity views, that being that they rule out our being biological organisms also, due to the fact that psychological continuity is not necessary or sufficient for human organisms to persist. This is evident from observing the persistence of a human embryo, done without any psychological continuity. This creates problems for psychological continuity by again suggesting that there can be two simultaneously existing from one, one being a thinking person and the other being a thinking organism distinct from it. Known as the thinking-animal objection, the most popular defence against it would be to make the claim that while sharing with it our brains and displays of consciousness and intelligence, human organisms are simply incapable of thinking and existing without consciousness, therefore making it so that there are simply no thinking animals that could create problems against the psychological continuity view. This argument is hard to defend as to say human organisms lack the ability to be conscious and intelligent, seems to then say that no biological organism could have any mental properties at all, threatening to almost render human organisms as zombies, philosophically speaking, beings physically and behaviourally identical to conscious beings, but lacking that key consciousness, which also begs the question of why it is that beings cannot possess consciousness. 

To tackle the problem of the existence of a self or our personal identity through the perspective of psychological continuity is a reductionist view, and through arguing this view, Parfit says that to debate over the existence of such a thing is not what matters, rather it is survival that matters, and that presupposes personal identity. Even separated from the concept of personal identity, psychological continuity is said to contain all that one will need to deem important about their own survival, in scenarios ranging from the splitting of the brain or complete transference of brain to a new body, to what becomes of us after death. This is all to say, in conclusion, the question of self and personal identity is intimately connected to the question of our persistence and survival, and so even though the myth of the self remains unresolved, psychological continuity allows us to better imagine the ever-changing yet also unchanging nature of our essence, and how this essence might ensure its survival, and by extension, our survival.