From the lucid explanation here cited (and from a following paragraph too long to describe p. 433), we see that there is no real distinction between Judgments in Comprehension and Judgments in Extension; that the _appearance_ of distinction between them arises from the customary mode of enunciation, which custom is here accounted for; that the addition to the theory of the Syllogism, for which Sir W. Hamilton takes credit, is alike troublesome and unprofitable. The like may also be said about his other innovation, the Quantification of the Predicate. Still more extensive are the changes (as stated by himself) which this innovation would introduce in the canons of Syllogism. Indeed, when we read his language (Appendix to 'Lectures on Logic,' pp. 291--297) censuring generally the prior logicians from Aristotle downwards, and contending that 'more than half the value of logic had been lost' by their manner of handling it--we may appreciate the magnitude of the reform which he believed himself to be introducing. The larger the reform, the more it behoved him to be sure of the ground on which he was proceeding. But on this point we remark a serious deficiency. After laying down, with appropriate emphasis, the valuable logical postulate, _to state explicitly what is thought implicitly_, on which, Sir W. Hamilton says, 'Logic ever insists, but which logicians have never fairly obeyed--it follows that logically we ought to take into account the quantity, _always understood in thought_, but usually, and for manifest reasons, elided in expression, not only of the _subject_, but also of the _predicate_, of a judgment.'--('Discussions on Philos.,' p. 614.) Here Sir W. Hamilton assumes that the quantity of the predicate is always understood in thought; and the same assumption is often repeated, in the Appendix to his 'Lectures on Logic,' p. 291 and elsewhere, as if it was alike obvious and incontestable. Now it is precisely on this point that issue is here taken with Sir W. Hamilton. Mr Mill denies altogether (p. 437) that the quantity of the predicate is always understood or present in thought, and appeals to every reader's consciousness for an answer:--