What It Is To Be
Does identity matter?
As a metaphysical dilemma this question relates to the existence of objects over time. How does a single object or entity persist through change? Exactly what constitutes the ‘nature’ of a person? When — or, perhaps more specifically, under what conditions — does a person come in to and out of existence? If we were, say, to hold a position stating that personal identity doesn’t matter at all, why are people concerned for their own survival? And in turn, why do people fear their own death and the threat of non-existence?
These existential questions above all revolve around ideas of ontology, ethics, human consciousness, and the self to ground the concept of personal identity. However, not everyone is an advocate of this position. One such detractor is British philosopher Derek Parfit, who stated in his seminal work of moral philosophy, Reasons and Persons (1987), with several notable revisions and corrections, that we are not separately existing entities and that our identity is not always determinate.
To explore Parfit’s claims, we need to first understand his explication of qualitative and numerical identity, his reductionist arguments in favour of the Psychological Criterion or psychological continuity, and how this view is differentiated from positions of physical continuity, along with his explanation for the unity of consciousness.
What is Personal Identity?
To begin, let’s clarify the difference between categories of qualitative identity and numerical identity. For Parfit, these categories both refer to claims of “sameness, or identity,” however they quantify or measure different aspects of an object: qualitative identity refers to the sharing of properties or characteristics, whereas numerical identity requires an object to be “one and the same” (Reasons 241) with itself.
As Noonan and Curtis note, qualitative identity is a matter of degree; things can be more or less qualitatively identical. However numerical identity requires total, or absolute, qualitative identity; a case of literally being the one and the same object. Therefore, as Parfit explains, questions of personal identity will typically rest on notions of numerical identity, where certain kinds of qualitative change can destroy the numerical identity of an object, or in our case, a person:
If certain things happen to me, the truth might not be that I become a very different person. The truth might be that I cease to exist — that the resulting person is someone else. (Reasons 241)
To arrive at his position that personal identity is not what matters, Parfit first defines a number of important identity criteria. In the ‘standard view’, the criterion of identity over time for most physical objects is described in terms of spatio-temporal physical continuity. This may include the continued existence of apparently static objects (i.e. a rock or a building), or objects which move in regular ways that trace physically continuous spatiotemporal paths (i.e. the Moon and its orbit through space). However, it is also possible for physical objects to continue to exist while undergoing qualitative changes to their physical continuity (i.e. a caterpillar and a butterfly).
Criterions of Personal Identity
Below are Parfit’s definitions for the Physical and Psychological Criterions of personal identity:
The Physical Criterion: (1) What is necessary is not the continued existence of the whole body, but the continued existence of enough of the brain to be the brain of a living person. X today is one and the same person as Y at some past time if and only if (2) enough of Y’s brain continued to exist, and is now X’s brain, and (3) this physical continuity has not taken a ‘branching’ form. (4) Personal identity over time just consists in the holding of facts like (2) and (3). (Reasons 243–44)
The Psychological Criterion: (1) There is psychological continuity if and only if there are overlapping chains of strong connectedness. X today is one and the same person as Y at some past time if and only if (2) X is psychologically continuous with Y, (3) this continuity has the right kind of cause, and (4) it has not taken a ‘branching’ form. (5) Personal identity over time just consists in the holding of facts like (2) to (4). (Reasons 247)
From these definitions, Parfit’s view of psychological continuity can be seen as an extension of Locke’s experience-memory account of personal identity, which includes further considerations for intentionality, belief, and desire.
We can also view Parfit’s use of these criteria as being reductionist for two reasons: the fact of a person’s identity over time consists of the holding of certain more particular facts; additionally, these facts are impersonal, that is they describe without either presupposing the identity of this person, or explicitly claiming that this person exists.
To justify this reductionist claim, Parfit provides three additional claims:
1) We are not separately existing entities, apart from our brains and bodies, and various interrelated physical and mental events.
2) It is not true that our identity is always determinate.
3) The unity of a person’s consciousness and the unity of a person’s whole life can be explained without presupposing that the experiences in this life are actually had by this person. (Reasons 257)
In supporting the first claim, Parfit refers to the Cartesian pure ego of spiritual substances or the soul in order to reject views of persons as purely mental entities. For claims (2) and (3), Parfit considers these as conditional statements; therefore, because we are not separately existing entities, identity is not always determinate, and the unity of a person’s conscious experiences can be explained exclusive of ownership of those experiences.
From this line of reasoning, Parfit then contends that personal identity is not what matters. Instead, what matters is, in his own terms, Relation R: the property of “psychological connectedness and/or continuity, with the right kind of cause” (Reasons 256).
To explore the full implications of Relation R, Parfit dives into the realm of science fiction, theoretical physics, and paradoxes to make his case.
Simple Teletransportation and the Branch-Line Case
Parfit’s thought experiment goes something like this: There’s a machine on Earth called a ‘teletransporter’ which puts you to sleep, breaks you down in to constituent atoms before destroying you, then copies this information and relays it to another teletransporter on Mars at the speed of light. On Mars, the other teletransporter re-creates you from your information blueprint, reconstituting each atom in the exact relative position and configuration (Reasons 239).
This is Simple Teletransportation and is mainly one of travel. The crux being this: Is the ‘you’ on Mars the same ‘you’ who entered the teletransporter on Earth?
In Simple Teletransportation, I am destroyed before I am Replicated. This makes it easier to believe that this is a way of travelling — that my Replica is me. (Parfit, Reasons 240)
Parfit then qualifies this scenario with an additional problem: the teletransporter on Earth is modified so that instead of destroying you on Earth, it merely copies you, sends your information away and creates an exact replica of you on Mars. To make matters worse, not only can your Martian doppelgänger speak directly to you in the form of a bizarre conversational loop, the teletransporter on Earth has damaged your heart and cardiac system, leaving you with only days to live (and the you on Mars has no such complications).
The conclusion for this new Branch-Line case is clearly unsettling and raises some curious ontological and epistemological concerns: How do you know which ‘you’ is the real ‘you’? And is it possible for a person to exist in two places at once?
At the end of my story, my life and that of my Replica overlap… If we believe that my Replica is not me, it is natural to assume that my prospect, on the Branch-Line, is almost as bad as ordinary death. (Parfit, Reasons 240)
This raises some troubling issues. In the Simple Teletransportation case, the you on Earth and your Replica on Mars would be qualitatively identical, or exactly alike. However, in the Branch-Line case, you and your Replica would not be numerically identical.
For Parfit, adherence to the Physical Criterion implies rejecting the teletransporter as a form of travel — instead, it’s simply a perverse form of dying and death. Upon atomisation and destruction of your brain and body, the person you were effectively ceases to be, failing to meet conditions (1), (2) and (3) of the criterion, and thus failing to meet condition (4) as well. You cannot continue to exist because you do not have the same physically continuous body (Reasons 244).
The Psychological Criterion
In response to the Psychological Criterion, however, matters of personal identity become somewhat harder to justify. Parfit defines three types of the Psychological Criterion which differ on condition (3), the right kind of cause:
On the Narrow version, this must be the normal cause. On the Wide version, this could be any reliable cause. On the Widest version, the cause could be any cause. (Parfit, Reasons 247)
In the case of Simple Teletransportation, the you on Mars is a ‘new’ person, however they have exactly the same configuration of brain and body, and they are psychologically continuous with the ‘you’ who was destroyed on Earth. While Parfit acknowledges that this imaginary case of teletransportation is highly unusual, the cause should be considered reliable. Therefore, for the case of Simple Teletransportation, using both the Physical Criterion and the Narrow Psychological Criterion, your Replica would not be you; however, for the two Wide Criteria, your Replica would be you (Parfit, Reasons 248–49).
However, in the troubling Branch-Line case, Parfit seems dismissive of the potentially dire implications:
If personal identity is what matters, I should regard my prospect here as being nearly as bad as ordinary death. But if what matters is Relation R, with any cause, I should regard this way of dying as being about as good as ordinary survival. (Reasons 256)
For Parfit, this thought experiment forces us to change our attitude towards ageing and death, and implies a change in our views of human rationality and morality.
Okay, But Does Personal Identity Actually Matter?
There’s no denying that the role of death plays an important role in questions of human morality and ethics. Let’s now imagine a reversal of the final scenario.
The teletransporter on Mars is the one that is modified, the Replica of you on Mars is the one found to have heart and cardiac problems, and as a result, is given only days to live. How does this change our reaction to the paradox?
As David Hershenov notes in “Countering the Appeal of the Psychological Approach to Personal Identity” (2004), Parfit insists “that what we care about in normal cases of survival isn’t that we persist, but that our psychology does. We care about the being in which the physical realization of our psychological capacities are found” (9).
Now, I think it’s fair to acknowledge that imaginary or hypothetical cases of teletransportation are not strictly ‘normal’ cases. When you retain both physical and psychological continuity; you effectively are the exact same person, in both a qualitative and numerical sense of identity. However, it cannot be denied that there is still another ‘you’ in existence on Mars, with your memories, beliefs, and desires, and that you is now facing certain death.
In discussing prudential rationality, David Shoemaker uses Parfit’s logic to compare the interests of a present self or person, with those of one’s Much Later Self (MLS):
While it is ordinarily thought to be imprudent to discount the interests of one’s Much Later Self (MLS) just because that self will not come into existence for a long time, Parfit suggests that reductionism provides a different, more plausible reason to do so. Since one of the relations in R (connectedness) obtains by degrees, it is very likely it will obtain to a much reduced degree between me-now and my MLS than it will between me-now and my tomorrow’s self. But if R grounds my patterns of concern, and a reduced degree of connectedness is one part of R, then a reduced degree of connectedness justifies a reduced degree of concern. Thus, I may be justified in caring much less about my MLS than about my tomorrow’s self. This conclusion justifies discounting my MLS’s (expected) interests in favour of my present interests.
We can use this line of reasoning to extend a reduced degree of concern for your MLS to those of your Replica on Mars. Most people — especially those concerned with their own survival and who (we can hopefully assume) would find being responsible for the death of another person morally abhorrent — would find this reversed scenario deeply upsetting.
Actively denying the personhood of your Replica, purely on the basis of maintaining Relation R, along with psychological continuity and connectedness, appears to be ethically unjustified. Therefore, in this case, it appears that personal identity does matter.
The Biological Approach and Animalism
In The Human Animal: Personal Identity Without Psychology (2003), Eric Olson argues that “we are animals” and that as “human animals [we] do not have psychological identity conditions” (1). As another proponent of this biological view, Hershenov supports a position where a person is “essentially a living being that is unable to survive death as a corpse but did exist once as a mindless embryo and could survive in a permanent vegetative state [referred to as PVS disorder]” (2).
For Olson, cases of mindless embryos and PVS disorder present obvious difficulties concerning psychological continuity. A five-month-old foetus lacks the mental contents and capacities to meet Parfit’s Psychological Criterion and cannot feel anything more sophisticated than pain. In the case of PVS disorder, the subject’s cerebrum is severely and irreversibly damaged; all higher cognitive functions (e.g. rationality, conscious awareness) are not present, while lower brain functions remain, such as life‐sustaining bodily functions.
According to Parfit’s Psychological Criterion, any person who once was has ceased to be upon entering a state of PVS, as they do not retain any of their psychological features. However, no ‘death’ in a biological sense has occurred and there is no breakdown of living organisation:
Anencephalic babies and human vegetables are human animals that can live for years without a working cerebrum. Not only do they lack a mind, but they do not even have the capacity to develop a mind. That means that some human organisms would have radically different persistence conditions from those of others. (Olson 22–3)
While I believe it is incorrect to suggest that a certain human being has ceased to be a person in the cases of mindless embryos or PVS disorder, this is what Parfit’s account of personality identity and psychological continuity entails. Certainly, the divisive and ongoing discussion around issues such as rights to abortion, euthanasia, and assisted suicide indicates that personal identity does matter in these cases as well — at least to potential parents, family members, and loved ones.
The Embodied Mind Account
In The Ethics of Killing (2002), Jeff McMahan provides a criterion of personal identity known as the Embodied Mind Account, to overcome the shortcomings of Parfit’s psychological continuity.
McMahan’s view is one of that advocates for an individual’s egoistic concern for the future, where what matters is “the physical and functional continuity of enough of those areas of the individual’s brain in which consciousness is realized to preserve the capacity to support consciousness or mental activity” (67–68).
While this embodied mind view does not directly resolve our dilemmas in the cases of teletransportation, mindless embryos or PVS disorder (without further and lengthy clarification), it does suggest that aspects of physicalism imply that personal identity does matter. When faced with questions of human suffering, it is obvious that death plays a central role in arguing for the importance of personal identity.
What It Is To Be
In I Am A Strange Loop (2007), Douglas Hofstadter describes Parfit’s views on personal identity and psychological continuity as an “an extremely daunting and bold undertaking,” one that represents “a radical re-perception of what it is to be” (376).
Hofstadter compares Parfit’s achievement to what Albert Einstein accomplished by challenging classical conceptions of physics with special relativity in the early twentieth century, and how Parfit himself saw this new view of human existence as profoundly changing “his attitudes towards his life, his death, his loved ones, and other people in general” (377).
Considering Parfit’s own tragic passing in 2017, this statement becomes even more prescient. However, while Parfit’s reductionist arguments for psychological continuity remain compelling and thought-provoking, Hofstadter expresses some reservations:
What I find is this. I can believe this view at the intellectual or reflective level. I am convinced by the arguments in favour of this view. But I think it likely that, at some other level, I shall always have doubts…
At the reflective or intellectual level, I would remain convinced that the Reductionist View is true. But at some lower level I would still be inclined to believe that there must always be a real difference between some future person’s being me, and his being someone else…
It is hard to be serenely confident in my Reductionist conclusions. It is hard to believe that personal identity is not what matters… And it is hard to believe that, if I am about to lose consciousness, there may be no answer to the question “Am I about to die?” (378)
Truthfully, I find myself agreeing with Hofstadter’s notions here as well. Parfit’s arguments are indeed persuasive, however they are not impenetrable to objections from the intuitive and naturalistic view of personal identity. In terms of moral and ethical arguments, considerations of personal identity help to shed light on the nature of death, and in turn, pondering the nature of death allows us to realise how and why personal identity matters.
Works Cited
Hofstadter, Douglas R. I Am A Strange Loop. Basic Books, 2007, pp. 376–78.
McMahan, Jeff. The Ethics of Killing: Problems at the Margins of Life. Oxford UP, 2002, pp. 66–9.
Olson, Eric T. “Are People Animals?” The Human Animal: Personal Identity Without Psychology, 2003, pp. 1–40, doi:10.1093/0195134230.001.0001. Accessed 23 Aug. 2020.
Parfit, Derek. “Personal Identity.” The Philosophical Review, vol. 80, no. 1, 1971, pp. 3–27, www.jstor.org/stable/2184309. Accessed 22 Aug. 2020.
— . Reasons and Persons. 1984. Oxford UP, 1987, pp. 237–59.
