A Personal Identity Theory of Everything: A Synthesis of the Theories of Parfit, Olson, Wolf and Schechtman

The philosophy of personal identity has seen multiple popular and successful theories over the past few decades. In this essay, I will explain the ideas on personal identity of four philosophers: The Psychological Continuity account of Derek Parfit, the Animalism of Henry Olson, Susan Wolf’s critique of Parfit, and Marya Schechtman’s Narrative Self-Constitution view. It will naturally seem as though all these theories are conflicting theories – this is, I believe, the way all of these philosophers would see it as well (Wolf being a possible exception). However, I will argue that these accounts actually are compatible (maybe with some minor adjustments made) and when synthesised even form a stronger, more comprehensive theory. I will start by explaining Parfit’s theory of Psychological Continuity, contrast it with Olson’s animalism and see how they fit together. I will then explain in what way Wolf criticised Parfit and with this critique opened up a new field in the debate, that of ethics, and I will then show that Schechtman’s narrative view perfectly answers Wolf’s newly raised question of what matters. In this way I will show that all four philosophers can be seen as cooperating and their theories as strengthening one another when combined.

Before going into the different theories, it is necessary to get a bit more clarity on the different questions in play. Parfit provides us with an important distinction in approaching the topic of identity – there are two questions we can ask, the first being Q(1):‘What is the nature of a person’ and the second being Q(2):‘What is necessarily involved in the continued existence of each person over time’.[1] I will come back to this later with Wolf’s critique of Parfit, but for now this distinction will do to keep in mind in its current form.


  1. Parfit and Olson

Parfit tries to answer both questions, but the main focus of his argument is on the question of when one person is identical over time, Q(2). His reductionist answer to this question is that Person A at one point in time is the same person as Person B at another point in time when Person A has ‘enough’ overlapping chains of psychological connectedness, or in other words, psychological continuity with Person B.[2] Parfit calls this the ‘Psychological Criterion’ and with the introduction of this criterion he also introduces two more requirements for personal identity, namely ‘having the right kind of cause’ and that it can’t take a so-called ‘branching form’.[3] These won’t be particularly important to the discussion in this essay, but I think it important to have quickly mentioned them anyhow.

Parfit’s own reductionist response to the question regarding the nature of persons, Q(1), is that a person who has experiences, isn’t a ‘separately existing entity’, not separately existing in the sense that Parfit reduces the person to other things: physical and mental events – such as the brain and the body, and our mental experiences.[4] Seeing as Parfit doesn’t find this question particularly important, he spends less time arguing for this answer than he does for the Psychological Criterion.

Olson critiques Parfit and formulates an argument against Parfit’s answer to Q(1), which Olson believes by extension also counters Parfit’s answer to Q(2). Olson is an animalist, which means that he believes the nature of a person is such that a person is an animal. He gives us two forms of the Thinking Animal-argument, and here I will present the one which I believe is the strongest version: “1) There is a human animal located where you are. (2) That animal thinks. In particular, it has the same thoughts as you have. (3) If you share your thoughts with a being other than yourself, you cannot know that you are not that being.”[5] From this he draws the negative conclusion that even if we are not animals, we could never know it. With this conclusion, unless we can deny one of the premises, we need to acknowledge that we can’t say that a person is not an animal, which is as close as we can get to saying that a person is an animal without actually drawing that conclusion. It is still intended to be a critique of Parfit, seeing as Parfit explicitly states we are a body and a brain and mental events, which Olson takes as saying that we are not animals.

Do Parfit and Olson really disagree on Q(1)? This is a crucial point to understand. It is from this apparent disagreement that Olson draws the conclusion that there is no psychological continuity needed for identity over time for animals,[6] resorting instead to what he calls the Lockean Life, life as pictured by John Locke which is ‘a complex, self-sustaining, physico-chemical event that imposes a remarkably constant form upon ever-changing particles.’ [7]

I believe Olson is mistaken when he thinks he has a different answer to Q(1) than Parfit. We need to keep in mind that Parfit is a reductionist and has given us a reductionist answer to Q(1). This means that we can, according to Parfit, describe all the events that make up a person without calling it a person. Parfit being a reductionist would therefore have no problem with saying humans are animals – but a reductionist would say that we are not fundamentally animals. If animals are made up of matter, why are we not fundamentally matter? This is an arbitrary preference. Why are we not fundamentally an organism (which would include plants)? Why are we not fundamentally an object? Why are we not fundamentally matter? Parfit avoids these problems with his reductionistic outlook, and Olson could perfectly accept this, in order for his theory to retain any credibility.

We are now left with two questions for Olson: Is Olson a reductionist with regards to identity, and would Olson agree that animals are made up of brain, body and psychological events? Seeing as he states that animalism is a materialist theory, meaning that animals are material beings (making it reductionist),[8] I think it is safe to assume that Olson would also be a reductionist with regards to identity, namely that we are human animals, which are organisms, which are alive (organic) bodies, which are simply bodies that have certain physico-chemical events.  This has also partly answered our second question: for Olson, we are not merely bodies and brains, but alive bodies and brains.

However, note that Parfit also added that we are made up of mental events – something Olson has ignored so far, as he talks about alive bodies and brains. Olson does acknowledge that there is the possibility for these specific human mental events which distinguishes human animals from other sorts of animals. This would still make a human animal an animal – just as a dog animal is a different sort of animal, but still an animal. So, I believe Olson is definitely in the position to accept that human animals are, at least partly, constituted by or identical to their mental events. This means that there isn’t necessarily a difference in the answers of both Parfit and Olson to the question of what the nature of a person is. A person is reducible to its parts; therefore, a person is a human animal. A human animal is identical to a human organism, which is an alive body and brain, together with certain mental events.

What is the difference then between the answers of Olson and Parfit to Q(2)? Olson’s answer to what it takes for a human animal to persist through time is the continuation of that animal’s life.[9] However, this doesn’t answer the question at all. Olson merely states that an animal has a life and for that animal to persist through time it needs to have the same life. But how is it that this animal is the same throughout its life? That is the question that needs answering, and Olson doesn’t give us an answer. Parfit does give us a clear answer. For Parfit, what it takes for a person to be the same through time is Relation R: ‘psychological connectedness and/or continuity with the right kind of cause’.[10]

We now know Olson hasn’t even given us any answer to the question, so it is difficult for something non-existing to disagree with an actual answer. Still, Olson explicitly says that he disagrees with the Psychological continuity theory.[11] However, persons are certain animals (an alive body and brain) with certain psychological events – as Olson acknowledged. Therefore, it perfectly compatible with Olson’s animalism that psychological continuity between different stages in a life is what makes sure that an animal had the same life in the past as it has now and will have in the future.
Having seen that their answers to Q(2) can be combined, where does their disagreement come from? It is a result of the fact that both authors place a different emphasis on a particular part of their answers. While they could agree on the nature of a person (as I have previously shown), Olson would still call this nature that of an ‘animal’, whereby he lays the focus more on the physical nature of the human. Parfit lays the emphasis on the mental factors and sees the body as mere carriers for these psychological events. What both proceed to do is to say that the factor on which they have put emphasis is the essential factor for identity over time. This brings us to Wolf’s critique of Parfit.


  1. Wolf’s Critique

In her article ‘Self-Interest and the Interest in Selves’, Susan Wolf critiques Parfit in a fundamental way. A part of Parfit I haven’t discussed here, is that from his reductionism about persons he thinks that it follows that we should also care less about our own person and care more about other people – you in the future won’t be that much different from someone else right now. Another part I have alluded already to is that Parfit places the importance of our being not on personal identity (and thus Q(1) ) but on Q(2), and therefore he places the importance not on personal identity but on Relation R, which is psychological continuity with any kind of cause. Wolf isn’t convinced Parfit is allowed to make the move he makes – he goes from an ontological or metaphysical question to an ethical question, he gets an is from an ought, he derives values from facts. From the fact that what it is that keeps us the same through time, Relation R, Parfit concludes that we ought to care about this relation and that our interests are mistakenly placed on persons.[12]

With this critique, Wolf not only dismantles Parfit’s approach but also that of Olson. Note that I have shown above that the difference in answering the question of how a person’s identity is maintained through time, Parfit and Olson both gave different answers because they implicitly placed the part of the human being they found most important on something else: for Parfit the mental events were of the most importance, for Olson it was our being an organism. With this move, Wolf has essentially modified the two questions concerning personal identity, Q(1) and Q(2). By reminding us we can’t derive values from facts, Wolf has added another question, Q(3), which asks ‘What should we care about in relation to personal identity?’. Her own answer to the question is that we should care about persons, as opposed to R-related beings. The difference between the two, Wolf argues, is that if we were to care about ourselves as persons, we should care about ourselves and identify with ourselves[13]– the opposite of what Parfit thought to have shown through his reductionism. She thinks this because persons can, in her opinion, lead more valuable lives than R-related beings because we can value our relationships with other persons more.[14]

An important point to note here is that the introduction of Q(3) leaves the answers of both Olson and Parfit alone. We can agree with the fact that persons are by their nature alive bodies, brains and mental events – and what keeps them the same through time is their R-relatedness. Wolf has simply pointed to the fact that our search for identity hasn’t yet come to a stop, because we still need to decide what we should careabout. It could be very well the case that we shouldn’t care about our nature and only our R-relatedness (a stance Parfit takes), or that we shouldn’t care about our R-relatedness but our being animals (a stance Olson takes). We could even decide that we don’t care about the nature of persons and their identity through time at all, and instead decide we should care about the health of the toenail on the big toe of our left foot.

With this in mind one can maybe already see how I wish to synthesize the theories of all four authors mentioned in my introduction, Parfit, Olson, Wolf and Schechtman. I have already shown how Parfit and Olson are to be synthesized: they agree on Q(1), and what it takes for the identity of human animals to remain stable through time is R-relatedness. With the introduction of Wolf’s Q(3), I wish to synthesize Parfit and Olson with Schechtman in the following way: while we are certain physical and mental events whose identity is kept stable by R-relatedness, we ought to care about something else – an answer Schechtman is going to give us.


  1. Schechtman’s Answer

I don’t think Schechtman is consciously working with the distinctions of the three questions in mind, as she identifies her own ‘Narrative Self-Constitution’ theory as a better psychological account than the ‘standard’ (read: Parfit) psychological account because it can account for four features she believes such an account should be able to support: moral responsibility, prudential concern, compensation and survival.[15] The way I read her however, is that what she actually is doing is giving an answer to Q(3), the ethical question, and not to any of the two ontological/metaphysical questions Q(1) and Q(2). This is already evident in the four features she mentions a psychological account should be able to support – they are to do with ethics and not with metaphysics. ‘When does someone have moral responsibility?’ isn’t a metaphysical question but an ethical one. It is for us to decide and we cannot find it in ontology.

The question of ethics is, thanks to Wolf, not located in either Q(1) or Q(2) but in Q(3). Schechtman isn’t giving us an ontological account, and this is abundantly clear in other parts of her writing as well: according to her, a narrative provides a phenomenological unity of consciousness over time which constitutes us as persons.[16] Because her case for personhood is a phenomenological one, it isn’t deriving values from facts – our experience of the world is filled with values and judgements. With this move she disregards the metaphysics of Parfit and focusses on the phenomenological, in which we can find the ethical.

We are now able to say what we should care about and how moral agency comes about. We should care about the narrative we (implicitly) make for ourselves. This means that our personhood is a story that we unconsciously construct about ourselves, and in relation to this story we are organize our lives and we experience the world.[17] Through this personhood we lead richer lives (as Wolf argued), and we can account for moral responsibility, prudential concern, compensation and survival because all of these things are traditionally associated with persons or selves, as opposed to R-related beings.
Note that I’m not going into the discussion about the nuances in and the difference between the different narrative-constitution accounts Schechtman raises in her article against Strawson, for those aren’t directly relevant for the point that I am trying to make, which is that through a narrative theory (no matter which one) we will be able to account for the ethical and thereby have answered the question of what matters to its fullest extent – and I have now synthesised the animalist, psychological and narrative theories.

To conclude: in this essay, I set out to find a synthesis of the theories of Parfit, Olson, Wolf and Schechtman. First off, I showed that there were two major questions that needed answering, a distinction Parfit made: Q(1):‘What is the nature of a person’ and Q(2):‘What is necessarily involved in the continued existence of each person over time’. I have shown that Olson and Parfit agree on their answer to Q(1). I have shown that Olson does not give us an answer to Q(2) and Parfit does give a coherent answer – I have also shown that Parfit’s answer to Q(2) is coherent with Olson’s answer to Q(1). In this way I combined the theories of Olson and Parfit to make them both stronger. However, after having discussed Wolf’s critique of Parfit – which has to do with the problem that we can’t derive the ethical from the metaphysical or the ontological – I added another question to the two questions, a question that Wolf implicitly states in her arguments. This question is Q(3): ‘What should we care about in relation to personal identity?’. Wolf answers her own question and states that we should care about persons, as opposed to Parfit’s ‘R-related beings’. To support this statement, I discussed Schechtman’s ‘Narrative Self-Constitution’ account, which bypasses the problem of grounding the ethical in the metaphysical and instead grounds the ethical in the phenomenological, as she describes ‘persons’ and what we should care about as a narrative through which we organize and experience our lives, and which provides a phenomenological unity to our experiences. The metaphysical and ontological answers of Olson and Parfit to Q(1) and Q(2) are still very much relevant, but not what is most important. I have synthesised all four views of Parfit, Olson, Wolf and Schechtman.




Olson, Eric. “Animalism and the Corpse Problem.” Australasian Journal of Philosophy 82,            no. 2 (June 2004): 265-274.

Olson, Eric. “An Argument for Animalism.” In Personal identity, edited by Raymond Martin and John Barresi, 318-334. Oxford: Blackwell, 2003.

Parfit, Derek. Reasons and Persons. Oxford: Oxford University Press, 1984.

Schechtman, Marya. “Stories, Lives, and Basic Survival: A Refinement and Defense of the Narrative View.” Royal Institute of Philosophy Supplement60, (May 2007): 155-178.

Wolf, Susan. “Self-Interest and Interest in Selves.” Ethics96, no. 4 (July 1986): 704-720.


[1]Derek Parfit, Reasons and Persons (Oxford: Oxford University Press, 1984), 202.

[2]Parfit, Reasons,206.

[3]Ibid., 207.

[4]Ibid., 223.

[5]Eric Olson, “Animalism and the Corpse Problem,” Australasian Journal of Philosophy 82, no. 2 (June 2004): 267.

[6]Olson, “Corpse Problem,” 270.

[7]Ibid., 273.

[8]Eric Olson, “An Argument for Animalism,” in Personal identity, eds. Raymond Martin and John Barresi (Oxford: Blackwell, 2003), 320.

[9]Olson, “Corpse Problem,” 273.

[10]Parfit, Reasons, 215.

[11]Olson, “Argument,” 328.

[12]Susan Wolf, “Self-Interest and Interest in Selves,” Ethics96, no. 4 (July 1986): 705.

[13]Wolf, “Self-Interest,” 710.

[14]Ibid., 709.

[15]Marya Schechtman, “Stories, Lives, and Basic Survival: A Refinement and Defense of the Narrative View,” Royal Institute of Philosophy Supplement60, (May 2007): 164.

[16]Schechtman, “Narrative View,” 167.

[17]Ibid., 162.


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