15: On Categorical Propositions which Contain the Pronoun 'Who'
On Categorical Propositions Containing 'Who' same thing is predicated of itself would be true. For example, if 'A chimera is something' were true, then 'A chimera is a chimera' would be true. And so no proposition in which something is predicated of the name 'chimera', taken significatively, can be more true than the proposition in which the name 'chimera' is predicated of itself. But this is compatible with its being the case that neither the one nor the other is true.
15: On Categorical Propositions which Contain the Pronoun 'Who'
Any proposition, categorical in form, which contains the relative pronoun 'who' should be given several exponents, since each such proposition is equivalent to a conjunctive proposition. However, such propositions must be dealt with in different ways, depending on whether they are universal, on the one hand, or particular, indefinite, or singular, on the other. For when such a proposition is particular or indefinite or singular, it is always equivalent to a conjunction of two propositions, which are composed of the antecedent and the relative pronoun 'he' (or a proper name) plus the other extreme—with no other change being made. For example, 'A man who is white is running' is equivalent to 'A man is running and he is white' or to 'A man is white and he is running'. Likewise, 'Socrates, who is running, is debating' is equivalent to 'Socrates is running and Socrates is debating'.
But if such a proposition is universal, then it is amphibolous, since it can have two senses. In one of these senses it is asserted that the predicate is said of everything that the whole phrase preceding the principal verb is said of—and nothing more is asserted.
And this is called by many the sense of composition, or it is interchangeable with that sense. In the other sense it is asserted that that which follows the term 'who' is predicated universally of the antecedent and that, similarly, the predicate is predicated