by Gabriel Furmuzachi

An identity story

The story goes like this:

… should the Soul of a Prince, carrying with it the consciousness of the Prince's past Life, enter and inform the Body of a Cobler as soon as deserted by his own Soul, every one sees, he would be the same Person with the Prince, accountable only for the Prince's Actions: But who would say it was the same Man? The Body too goes to the making of the Man and would, I guess, to every Body determine the Man in this case, wherein the Soul, with all its Princely thoughts about it, would not make another Man: But he would be the same Cobler to every one besides himself. I know that in the ordinary way of speaking, the same Person, and the same Man, stand for one and the same thing. And indeed every one will always have a liberty to speak, as he pleases, and to apply what articulate Sounds to what Ideas he thinks fit, and change them as often as he pleases. But yet he will inquire, what makes the same Spirit, Man, or Person we must fix the Ideasof Spirit, Man, or Person, in our Minds; and having resolved with our selves what we mean by them, it will not be hard to determine, in either of them, or the like, when it is the same, and when not.

(John Locke, Essays Concerning Human Understanding, Second edition, 1694, chapter 27, section 15; Locke's orthography and emphases).

This is one of the most fertile thought experiments in the history of philosophy. It has been quoted numerous times, discussed, criticized, praised, etc. Who is really the Prince and who is the Cobbler? What makes one be identical over time? What is that which accounts for personal identity? John Locke tried to answer this kind of questions throughout his Essay Concerning Human Understanding. What follows is an attempt to sketch Locke's position on personal identity.

Locke wrote the Essay... having as background the Scholastic tradition. However, he was up to date when it came to knowing the new opinions in physics (he was one of the few at his time who possessed a complete edition of Galileo's work, for example) and he made extensive use of this knowledge in the presentation of his ideas. Moreover, he had a very good understanding of Cartesian philosophy and he was never reluctant in criticizing it. For example, Descartes thought it possible that, given certain "primitive" truths (e.g., that the true and immutable nature of body is extension, the true and immutable essence of mind, thought), one could deduce new factual truths about the world. As Schankula pointed out in Locke, Descartes, and the Science of Nature:

Locke clearly believed that while the Scholastic principles were self-evident (intuitively true) but 'trifling', the Cartesian principles were mere hypothesis, in fact stipulative, 'nominal' definitions masquerading as statements of real essence. Consequently, he believed that while the Scholastic method of deducing from principles was a legitimate, if limited, method of teaching, the Cartesian method of deducing from true and immutable essences clearly and distinctly perceived in intellectual God-guaranteed intuitions was a bogus method of discovery. The deductions themselves did not (indeed, could not) decide; they simply begged any factual question at issue. (1)

In other words, Locke tried to distance himself from the two dominant approaches of his time. He cleverly done away with the Scholastic principles by saying that they are true but, nevertheless, trifling. Then, he allowed himself to philosophically argue with Descartes, blaming him for not being aware of the metaphorical world in which he dwelt. Indeed, by putting together scientific discovery and geometrical demonstration, Descartes ended up giving problematic solutions to crucial matters. Locke believed that physical explanation of phenomena and theoretical explanation should not be regarded as identical (as Descartes seems to have done). They pertain to different realms and connecting them would only lead to making a category mistake (or, as Ryle called it, a "category confusion").

Thus, Locke cleared the ground for his own ideas. And then, his answer to the question of personal identity was brought forth: "consciousness makes personal identity", he writes in Essay…, II, 27, 10. Thus, the Prince is still a Prince inasmuch as his consciousness is not altered. His identity as a person is not disturbed. But what about the others? What about the people around him, who would only see the body of the Cobbler? Would they know that he is the Prince? Following Locke, something else must be taken into consideration here. We are talking about two different things or, as Wittgenstein would say, there are two different language games here. There is first the concept of "person" and when we talk about personal identity, "sameness of consciousness" is enough. However, there is something more - there is the concept of "man" which is different from that of a person but which cannot be avoided when talking about identity. For Locke, in the same way that we have continuity of consciousness through time we should have continuity of the body through time, so that our participation in the world would not be short-circuited by a sudden change of the body or of consciousness and therefore, of the way we perceive reality and live in it.

But let us go back to the idea that "consciousness makes personal identity". Prima facie, this statement is problematic in the context of the Essay… because it comes right after Locke talked about consciousness being interrupted by forgetfulness, amnesia, sleep, and so on (these would be the most common objections which one would raise against Locke and his views on personal identity). Why would he bring them into discussion here? One possible answer is that conceiving of personal identity as a thinking substance implies that one has to admit that the thinking substance does not think in a continuous manner (how one could explain then amnesia, for example?). This position is meant to be directed against Cartesianism (2) and should not be conceived as a flaw in Locke's argument.

In order to avoid the complications one would arrive at by following Descartes' position, Locke chooses to talk about personal identity without using the notion of substance. Consciousness determines the identity of a person. Now, what does "sameness of consciousness" over time mean?

It seems that what Locke tries to denote by using the idea of "sameness of consciousness" is the fact that consciousness is a pattern for the relation between two mental states. Having the same consciousness means, therefore, having the same pattern of connecting different mental states through time. Thus, it does not matter if substances change. What matters is how the change occurs. Our bodies change over time, for example, though we are the 'same' people. What is important is that our bodies don't change suddenly. A sudden change would mean a different way of perceiving the world. The Cobbler's body has a certain way of "being in the world". It reacts to certain events and does not notice others, it performs certain actions in specific ways. The same with Prince's body. However, when Prince's soul, "carrying with it its consciousness" wakes up in a body through which it is not used to interact with the world, then we can expect that the world itself would not appear to it as it is. It might as well be a dream world, although a vivid dream world. The Prince would not know the difference between reality and dream. He would be himself to himself but not to the others.

As Gibson pointed out, "Mind is aware of itself as well as of other things, and cannot be aware of anything at all without being aware of itself. We are, moreover, aware of our minds, e.g. thinking, doubting, knowing, willing and obtain by these means an entirely distinct kind of simple ideas which Locke calls ideas of reflection, distinct from ideas of sensation." (3) The "idea" is to stand for "whatever is the object of understanding when a man thinks."(I,1,8) While we cannot perceive the operation of our minds by our senses or represent them to ourselves in imagination, we can undoubtedly make them objects of our thoughts, and, to do this, is to have an idea of reflection. These operations occur however in our mind, and we are the only ones who are aware of them. One cannot make public the way one is conscious of himself, or as said above - the Prince would be himself to himself but not to the others. The idea of any past action does not have an objective existence. If one is to recollect an idea of a past action one has to make use of the same operations one had to do in the past and these are the facts which testify for sameness of consciousness.

Let us now see what is this connection between continuity of life and sameness of consciousness. For Locke, two masses of atoms are identical at different times if they consist of the same atoms at both times; however, many types of things can be quantitatively identical even if the material that composes them changes. Now, following Locke, one can say that in what living organisms (plants and animals) are concerned, they remain quantitatively the same if they consist of atoms organised into the same pattern with the same set of basic biological function existing continuously over time. In other words, identity of an organism consists of continuity of life (or biological) processes. Moreover, talking about human beings, we can say that we are simply a type of animal and the criterion of identity for human beings (for "men" and not for "persons") is thus the same as the one for animals. The idea of a rational being alone does not count for the idea of a man; one has to add, beside that, the other idea - of a body "so and so shaped". (4) Therefore, the idea of a man is the conjunction between the idea of a rational being and that of a body with a human shape. Thus, we cannot talk about the Prince in the story as being the same Prince. We can talk about the Prince being the same person but not as him being the same Prince.

Thus, the criterion of identity for man is the continuity of life. This means that somebody is the same man even if his body changes through time (but it has the same pattern with the same set of basic biologic functions) as long as he has the capacity of reasoning and has a continuous life. Then, the criterion of identity for person is the sameness of consciousness. Consciousness is then a link through time and that what it links are personal substances or selves. Now, what is a personal self? The only thing which, for Locke, differs in the definition of the self to that of person is the word concern.(5) This has to do with the ethical issue of Locke's philosophy because the self is the one which has responsibilities and acts according to moral laws. Locke treated the relation of personal identity between one's present and past self as a relation between different things, not as implying that one's past and present self together form one identical person.

To be as short as possible, Locke's moral claim is that if we punish a present self for the acts of a past self to which it is not linked by a sufficient chain of memories (even if it is linked by a chain of biological development), then "we act no more responsibly than did the Restoration Government if it supposed that by hanging Cromwell's corpse it was punishing Cromwell." (6)

But what is the relationship between consciousness and the immaterial substance? In which way the immaterial substance is a support for consciousness? Locke is clever enough to work with the presupposition that immaterial substance exists. This would have spared him from getting into troubles with the Church. However, in his view, immaterial substance alone does not account for personal identity. Consciousness is that which determines personal identity but it is not a substance, it is just a sum of relations among ideas of reflection. If there is a substance, it cannot be known since we do not have the possibility to have an idea of it in perception. These ideas can be thought because of the immaterial substance, but their mere existence does not testify for the existence of the substance itself as a substance.

The first edition of the Essay... did not contain the chapter in which he talks about personal identity. In the second edition, however, after the chapter where he talks about "relations", he placed a new chapter - on personal identity. Why there?, one might ask. And why this chapter? A possible answer might be that he regarded the problem of relations in close connection to that of the personal identity. Locke saw the issue at stake with other eyes than his predecessors did. Knowledge was constituted by the perception of a relation, more precisely, a relation between ideas. If for Scholastics knowledge was represented by the apprehension of the ideas, for Locke this was no longer valid: knowledge was the apprehension of the relations between forms or ideas. Ideas are the immediate objects of the mind in thinking. Moreover, he retained the old notion of the separate, independent substances, each of which having its own inner constitution or essence. Knowledge, which only grasps relations cannot grasp an inner essence which, therefore, remains hidden and mysterious. Being familiar with this conclusion is a must for anyone studying Locke, as John Dewey wrote, "In final analysis, the opposition between the inner constitution and essence (which Locke retained from prior metaphysics) and the relations which are knowable (his own contribution) is the source of an opposition which we are familiar with as the Lockean contrast between idea and object."(7)

A question might arise at this point: what is the connection with Locke's exposition of the problem of personal identity? The answer that could be given is that Locke's understanding of personal identity changes the usual perspective. For him, that which makes a person being the same over time is not a substance but a relation. This is the idea which I have followed when analyzing this passage.

Locke defines substance in his Essay... as that in which qualities inhere (II, 23, 1). A quality is a propriety of an object that acts in our minds to cause an idea. The substance itself is the thing that has certain qualities. But if one tries to understand what substance is, Locke would answer that the idea of substance is "obscure" (II, 23, 1-3). Thus, when it comes to the problem of personal identity, Locke seems to say that there is no underlying substance apart from these qualities. A person is not a substance, to put it more clearly. The essence of a person is the consciousness, and only the consciousness of that person. Consciousness is a matter of "organisation" and not a matter of substance. The person – that which include one's identity -- is completely independent of the particular substance: it is nothing but a certain organisation which is consciousness. This means that the same body (as substance) could potentially house different persons at different times, and the same person could theoretically be housed by different bodies at different times (II, 27, 10). So, the Prince in the story is still a Prince inasmuch as his personal identity has been preserved. But we cannot say the same about him as a Man, as a whole human being.

To conclude, does Locke seem to be giving birth to a new substratum? Something which can be put next to both the material and immaterial substance? My opinion is that, for Locke, consciousness that makes a person to be the same person is just a nominal essence and not a real one. The affirmation can be regarded as being too radical and Locke did not even express as such, nor did he claim it. But the reasons I put on display above might support me in affirming such a thing.


  1. Schankula, H.A.S.- Locke, Descartes, and the Science of Nature, in Ashcraft, Richard (editor) – John Locke, Critical Assessments, vol. IV, p. 391)

  2. What does the thinking substance do in these cases? How can a substance not think if it was made for thinking?

  3. Gibson, James – John Locke, in in Ashcraft, Richard (editor) – John Locke, Critical Assessments, vol. I, p. 12

  4. For I presume it is not an idea of a thinking or rational being that makes the idea of a man, in most people's sense, but of a body, so and so shaped, joined to it; and if that be an idea of a man, the same successive body not shiffted all at once, must, as well as the same immaterial spirit, go to the making of the same man. – Locke, Essay..., II, 27, 8

  5. The self is that conscious thinking thing (whatever substance is made up, whether spiritual or material, simple or compound, it matters not) which is sensible, or conscious of pleasure and pain, capable of happiness and misery, and so is concerned for itself as far as that consciousness extends. Essay…, II, 27, 17

  6. Hugues, M. W.- Personal Identity: a defence of Locke, in Ashcraft, Richard (editor) – John Locke, Critical Assessments, vol. IV, p. 561

  7. Dewey, John – Substance, power and quality in Locke, in Ashcraft, Richard (editor) – John Locke, Critical Assessments, vol. IV, p. 54