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Knowledge as ‘True Belief Plus Individuation’ in Plato


In Republic V, Plato distinguishes two different cognitive powers, knowledge and belief, which operate differently on different types of object. I argue that in Republic VI Plato modifies this account, and claims that there is a single cognitive power, which under different circumstances behaves either as knowledge or as belief. I show that the circumstances which turn true belief into knowledge are the provision of an individuation account of the object of belief, which reveals the ontological status and the nature of the object. Plato explores many alternative candidates of individuation accounts of objects of true belief, which he discards. I conclude with a Platonic sketch of a teleological account of individuation which would satisfy his requirements of turning true belief into knowledge.

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  1. 1.

    Williamson (2000: 21; see also 45).

  2. 2.

    One can pursue this topic in Nehamas (1975), Vlastos (1981a), Benson (1990), Rudebush (2009).

  3. 3.

    Cohen (2004).

  4. 4.

    For Socrates’ disavowal of knowledge see Gulley (1968), Vlastos (1971), Vlastos (1985).

  5. 5.

    Vlastos (1985), p. 12.

  6. 6.

    “When a person at the time of learning writes the name of Theaetetus, and thinks that he ought to write and does write Th and e; but, again, meaning to write the name of Theodorus, thinks that he ought to write and does write T and e—can we suppose that he knows the first syllables of your two names?

    We have already admitted that such a one has not yet attained knowledge.” (Theaetetus 208a).

  7. 7.

    See also, e.g. “‘The soul, then, as being immortal, and having been born again many times, and having seen all things that exist, whether in this world or in the world below, has knowledge of them all”. (Meno, 81d).

  8. 8.

    For the existential reading of the knowledge arguments see, for example, Cross and Woozley (1964); Hintikka (1973); Stokes (1992).

  9. 9.

    Cross and Woozley (1964), Ch. 7–9.

  10. 10.

    Allen (1960), Vlastos (1965), Gosling (1968), Annas (1981), Smith (2000), Sedley (2007), and Gonzalez (1996) combining the existential and the predicative interpretations.

  11. 11.

    Gail Fine (1978, 1990). A critical discussion of the veridical interpretation is further offered by Job van Eck (2005).

  12. 12.

    A comprehensive survey of the interpretative scene of Plato’ theory of knowledge and belief in Republic V is given by de Harven.

  13. 13.

    Williamson (1997), p. 717.

  14. 14.

    Williamson (2000), 41–48.

  15. 15.

    Williamson (2000), 47.

  16. 16.

    I read the text, 477d4, 478a12-b5 as claiming them to be different objects, rather than different classes of objects.

  17. 17.

    Nehamas (1975) 109.

  18. 18.

    Pritchard (2012) 72.


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Correspondence to Theodore Scaltsas.

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Scaltsas, T. Knowledge as ‘True Belief Plus Individuation’ in Plato. Topoi 31, 137–149 (2012). https://doi.org/10.1007/s11245-012-9148-5

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  • Plato
  • Epistemology
  • Knowledge
  • Individuation