ONT Re: Doctrine of Individuals
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| The old logics distinguish between 'individuum signatum' and 'individuum vagum'.
| "Julius Caesar" is an example of the former; "a certain man", of the latter.
| The 'individuum vagum', in the days when such conceptions were exactly
| investigated, occasioned great difficulty from its having a certain
| generality, being capable, apparently, of logical division. If we
| include under the 'individuum vagum' such a term as "any individual
| man", these difficuluties appear in a strong light, for what is true
| of any individual man is true of all men. Such a term is in one sense
| not an individual term; for it represents every man. But it represents
| each man as capable of being denoted by a term which is individual; and
| so, though it is not itself an individual term, it stands for any one
| of a class of individual terms. If we call a thought about a thing
| in so far as it is denoted by a term, a 'second intention', we may
| say that such a term as "any individual man" is individual by
| second intention. The letters which the mathematician uses
| (whether in algebra or in geometry) are such individuals
| by second intention. Such individuals are one in number,
| for any individual man is one man; they may also be regarded
| as incapable of logical division, for any individual man, though
| he may either be a Frenchman or not, is yet altogether a Frenchman
| or altogether not, and not some one and some the other. Thus, all
| the formal logical laws relating to individuals will hold good
| of such individuals by second intention, and at the same
| time a universal proposition may at any moment be
| substituted for a proposition about such an
| individual, for nothing can be predicated
| of such an individual which cannot be
| predicated of the whole class.
|
| CSP, CP 3.94
|
| Charles Sanders Peirce,
|"Description of a Notation for the Logic of Relatives,
| Resulting from an Amplification of the Conceptions of Boole's Calculus of Logic",
|'Memoirs of the American Academy', Volume 9, pages 317-378, 26 January 1870,
|'Collected Papers' (CP 3.45-149), 'Chronological Edition' (CE 2, 359-429).
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