On Identity

What is the nature of personal identity?

This essay largely labours to clarify the above question, as first strictly considered by John Locke in Book 2, Chapter 27 of On Identity and Diversity. None of what is written here is intended to be a rigorous read but rather an effort to entertain contraries for the sake of contemplation.

The measure of identity in the diachronic sense is revealed by comparing the existence of a person existing at a certain time, with that which exists in another time. Thus, an essay concerning the dimensions of congruence between one's present and past self must inadvertently first seek to clarify the nature of this self. The problem of personal identity stands central to this.

Reid maintains that identity "is too simple a notion to admit of logical definition" [1]. Hume claims that the question of personal identity is "impossible to answer without a manifest contradiction and absurdity" [7]. Reid's and Hume's arguments, prima facie, explore the nature of personal identity without dealing with it directly; they go insofar as rendering it simple and unanalyzable. Locke, uniquely, identifies that "consciousness makes personal identity" [9]. But the abstractness of consciousness, a priori, is an unsuitable clarification too since it calls upon more problems than it really solves. Therefore, we must deal with the problem in logical divisions that are analytical:

I. What is the nature of personal identity?
II. What is the arbiter for continued existence of the above?
III. To what degree and in what senses can personal identity be defined?

To firmly assess in what sense I am the same as some arbitrary point in the past presupposes an answer to the questions "what am I?" and "what makes me who I am?" The union of these questions can be reduced to a problem of personal identity. The second question deals with the problem of persistence. In other words, what does it take for a person to persist from one time to another? Without knowing how existence subsists over time, the ways in which it remains the same cannot be answered. The third question then builds on the results of the second. We consider an argument inspired by the Ship of Theseus. We then contend that propositions of identity resolve into matters of contingency where it is not possible to offer a definitive resolution but rather only a relative one.

I. What is the Nature of Personal Identity?

Identity is the relationship that a thing bears to itself, as compared to other objects [15]. Personal identity is viewed by Locke as the product of consciousness over time, i.e., "sameness of the rational being." Thus, it follows that our identity only persists so far as our consciousness does. However, it can be equally argued that by consciousness, Locke actually meant memory [9], but the faculties of consciousness and memory differ in that the former translates to knowledge of the present while the latter is that of the past. So, Locke's argument may be reformulated in saying that personal identity consists in episodic memory. Yet I contend that present consciousness of the past is not necessary to our personal identity, for our personhood does not cease in those instances we cannot remember. In other words, to say that memory constitutes personal identity or at the very least is necessary for us to be the same is to say that persons have only existed through the times they can remember. This is a manifest absurdity.

Contrary to Locke's views, Hume held persons as a bundle of different perceptions that succeed each other with "an inconceivable rapidity" [7]. In this sense, successive rapid changes often allow one to confound diversity with the notion of identity. I would, however, contest that to say identity is an illusion offends common sense since it implies I am in no ways the same as the person I was yesterday. This is an absurd result. I believe that our understanding of identity is in accordance with the proportion of changes relative to the body that suffers those changes, just as how the addition or diminution of a leaf would not be sufficient to bestow diversity upon a tree.

II. What is the Arbiter for Continued Existence of the Above?

For clarity, I will reformulate the persistence question as follows: if a person A exists at a time t1 and a person B exists at another time t2, under what conditions can we argue that they are the same? It is worth noting that diachronic identity is a controversial notion since time is itself identified by change. Heraclitus' dictum that one could not step foot in the same river twice captures this, along with Hume's idea of identity being a fictional concept.

The Memory and Bodily Criteria

It is apparent that Locke's theory confounds evidence of personal identity with the very idea of personal identity; this is also reflected in Reid's criticisms [1]. Episodic memory is merely a yardstick to gauge that I exist but not a yardstick to gauge that I exist continuously. For logically, if A at a time t2 > t1 remembers an event at time t1, then it is sensible to say A existed at time t1. However, while memory of an event at time t1 entails that A existed then, it does not necessarily mean that the intelligent agent viewing the event at t1 is identical with the agent that exists at t2. Thus, I contend that memory is a very fallible metric for persistence.

Further, Reid and Locke both agree that mental faculties such as memory are not continuous and that personal identity supposes a continued existence [2]. The result is a manifest contradiction, allowing us to discard the memory criterion. As far as any brute-physical relation is concerned, we may not identify as different persons even after having suffered losses of bodily faculties. In saying that a man has lost a limb, we do not mean that the man is now a different person. So, I contest that personal identity is not ascribed to parts of the body, or the body as a whole. This discards any brute-physical relation.

Anticriterialism

Most philosophical views (be it those of psychological continuity or those of brute-physical relations) agree that there is a criterion responsible for our persistence; this is challenged by anticriterialism, which is the thesis denying the existence of any such criteria for diachronic identity. Anticriterialism supposes that psychological and physical continuity are evidence for persistence but do not always guarantee it [13]. In other words, there are no metaphysically informative necessary and sufficient conditions for the persistence of persons.

The general consensus is then understood as any proposed criterion for personal persistence will be uninformative, unnecessary, or insufficient [4]. The motivation in espousing anticriterialism stems from the results of criterialism; namely, the thesis that obtaining one contingent state of affairs necessarily implies obtaining another distinct contingent state of affairs is unacceptable [13]. It has been shown, however, that in some cases, espousing anticriterialism leads to absurd results [4]. This, however, is still subject to modern debate [14, 18].

Aristotelian Changes

In circumventing the above problems, I propose that we may distinguish between "accidental" and "essential" changes in the Aristotelian sense. Accidental changes are assumed as ones which do not manifest any changes such that an object's core nature remains the same. Essential changes, on the other hand, are those that do not preserve the identity of a being [6]. In distinguishing between the two, one may argue that it is certainly possible for a changing being to remain the same thing before and after the change so long as the only changes suffered are accidental. This is extended with relative relations of identity wherein we cannot simply say that two bodies are identical; instead, we require a sortal yardstick that serves to tell us in which sense the two bodies are identical.

III. To What Degree and in What Senses Can Personal Identity Be Defined?

Let's momentarily propose that persons are, in some senses, like the Ship of Theseus, with ideas and virtues refurbishing themselves. We then ask whether the person who has suffered those experiences is the same as the one who has not. In other words, as we refurbish or discard ideas and perceptions, at what point do we stop bearing personal identity with our past selves? In answering this, I contend that refurbishment only affects one's accidental properties. It is easy to see this since persons do not lose their personhood (an essential property) through time. Therefore, at no point in this process may we contest that a person has ceased being a person or is now a different person.

Further, I argue that one is the same as their past self in all the essential senses. As far as the accidental senses are concerned, I contend that when a succession of such changes occur, we are not hesitant to attribute identity since the alterations are trivial. However, this perspective resolves into a matter of contingency depending on one's notions of essential properties, identity, and diversity.

We have now shown that facts concerning personal identity are relative to the framework and are not overarching and valid to every theory addressing identity but only to those whose fundamental descriptions are the same. We have shown some manifest absurdities and contradictions, allowing us to narrow the metatheory of personal identity. Further, we argue that the question resolves into a matter of contingency and therefore, one may arrive at different answers depending on the foundational ideas one chooses to begin with. One of the reasons we may be reluctant to accept such a conclusion about the arbitrariness of personal identity is because our personal experiences imply a continuity which might well be no more than an illusion of coherence. Ultimately, the determination of sameness between my present self and my ten-year-old self depends on the sense in which the question is posed, rendering it relative to the framework applied.

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