John Locke (1694), “Of Identity and Diversity”, An Essay Concerning Human Understanding, Book II, ch. xxvii. The chapter was added in the second edition (London, 1694); the first edition of 1690 does not have it. The text read is that of the posthumous sixth edition (1710), as reprinted in Philadelphia by Troutman & Hayes (1853) and transcribed on Wikisource.
On the citation. The brief’s details are right: the chapter, its title, and its addition in the second edition of 1694. Four things to add:
- Identifier. The 1694 chapter has no DOI. The URL is the Wikisource
page of the text actually read.
published:is the second edition, by year only, since no source I reached gives a month. - Edition read. The sixth-edition text, not the 1694 one. Locke revised the Essay through later editions, so a wording quoted here is the final text’s and may differ from the 1694 printing, which I did not see.
- Section numbers are §§1–29 as in the Troutman & Hayes text. They match the numbering the modern literature cites (§8 holds Prince Maurice’s parrot, §26 calls “person” a forensic term).
- Project Gutenberg’s text is not safe to cite. eBook #10615 numbers the chapter in 31 sections, omits Prince Maurice’s parrot from §8 and the sentence on why drunkards are punished from §22, and garbles §§14 and 24 (“particles of smaller” for “particles of matter”).
Key takeaways
- Identity is relative to the kind. “It being one thing to be the same substance, another the same man, and a third the same person” (§7). A mass of atoms is the same while it has the same atoms; an oak, a horse and a man are the same while they share one continued life in changing matter (§§3–6).
- Personal identity is the sameness of consciousness. “As far as this consciousness can be extended backwards to any past action or thought, so far reaches the identity of that person” (§9). Substance does not matter: one person may span several substances, and one substance may host several persons (§§10, 13–14, 23).
- Man and person come apart. The prince’s soul with its consciousness in the cobbler’s body makes “the same person with the prince”, but nobody would say “the same man” (§15).
- “Person” is “a forensic term, appropriating actions and their merit” (§26), and personal identity grounds “all the right and justice of reward and punishment” (§18).
- The view is offered with its theological backstop. That consciousness is never transferred between thinking substances is “best resolved into the goodness of God” (§13), and the account is defended as pardonable “in this ignorance we are in of the nature of that thinking thing” (§27).
Standing in the record
Filed on 2026-10-02 at the owner’s request, to fill out the record’s coverage of identity, personhood and selfhood. NOTE-385 is the reading, and it placed the work: Active. This is where the psychological account of personal identity begins. Every later work the record holds on the persistence of persons, and those filed beside it, answer to it. Read it for its distinctions and its cases. Its thesis rests on a relation, “the same consciousness”, that it does not define and that later readers could take for memory, which is the reading Parfit’s quasi-memory repairs.
No anthology topic holds it, it carries no instruction for machine-learning practice, and the anthology does not hold it.
Where it meets the record:
- The survey of identity and ethics (LIT-130, NOTE-166) places Locke at the start of both its psychological criterion and its responsibility section. Locke’s “forensic” person is the first statement of the link the survey maps, from what persists to who is accountable.
- Floridi (LIT-136, NOTE-130), as that reading reports him, credits Locke with distinguishing kinds of sameness question and faults him for committing ontologically. Locke’s §7 and §28 are that distinction, and his own conclusion, that the difficulty “rather rises from the names ill-used”, is closer to Floridi’s deflation than Floridi allows.
- Velleman (LIT-292, NOTE-268) reads Locke as making survival a matter of memory alone, so that the prince and the cobbler could swap their beliefs and loves. The chapter’s own word is “consciousness”, extended to “thoughts and actions” and to concern for happiness (§§17, 26). That is wider than memory, though Locke’s examples are all of remembering.
- The extended self (LIT-097, NOTE-180). Locke’s little finger (§§11, 17) makes the boundary of the self the boundary of consciousness: the limb is part of me while I feel it, and not once it is cut off. Clark and Chalmers draw the boundary at coupling and endorsement, and so can put a notebook inside it. On Locke’s test the notebook is outside, since its contents are not something one is conscious of in the way one feels a hand.
- Where Am I? (LIT-405) stages Locke’s prince-and-cobbler case with a brain in a vat, and asks where, not who. Dennett’s “point of view” is Locke’s consciousness given a location.
The personal-identity works filed beside it on 2026-10-02 (Hume, Parfit’s “Personal Identity”, Williams, Lewis, Reasons and Persons) set out what became of the view. Parfit’s fission case is, by his own footnote, “implicit” in this chapter’s §18, where the severed finger keeps its own consciousness. The modern positions being filed in parallel by another agent, the animalist answer especially, take Locke’s “same man” for the person, which is the identification this chapter refuses.