§ 286. As we cannot be sure which of these two relations of A to B is meant, the predicate B has to be reckoned undistributed, since a term is held to be distributed only when we know that it is used in its whole extent. § 287. To say 'No A is B,' however, is to say that A falls wholly outside of B, which involves the consequence that B falls wholly outside of A. [Illustration] § 288. Let us now apply the same mode of illustration to the particular forms of proposition. § 289. If I be taken in the strictly particular sense, there are, from the point of view of extension, two things which may be meant when we say 'Some A is B'-- (1) That A and B are two classes which overlap one another, that is to say, have some members in common, e.g. 'Some cats are black.' [Illustration] (2) That B is wholly contained in A, which is an inverted way of saying that all B is A, e.g. 'Some animals are men.' [Illustration] § 290. Since we cannot be sure which of these two is meant, the predicate is again reckoned undistributed. § 291. If on the other hand 1 be taken in an indefinite sense, so as to admit the possibility of the universal being true, then the two diagrams which have already been used for A must be extended to 1, in addition to its own, together with the remarks which we made in connection with them (§§ 285-6). § 292. Again, when we say 'Some A is not B,' we mean that some, if not the whole of A, is excluded from the possession of the attribute B. In either case the things which possess the attribute B are wholly excluded either from a particular part or from the whole of A. The predicate therefore is distributed. [Illustration] From the above considerations we elicit the following-- § 293. Four Rules for the Distribution of Terms. (1) All universal propositions distribute their subject. (2) No particular propositions distribute their subject, (3) All negative propositions distribute their predicate. (4) No affirmative propositions distribute their predicate. § 294. The question of the distribution or non-distribution of the subject turns upon the quantity of the proposition, whether universal or particular; the question of the distribution or non-distribution of the predicate turns upon the quality of the proposition, whether affirmative or negative. CHAPTER V. _Of the Quantification of the Predicate._ § 295. The rules that have been given for the distribution of terms, together with the fourfold division of propositions into A, E, 1, 0, are based on the assumption that it is the distribution or non-distribution of the subject only that needs to be taken into account in estimating the quantity of a proposition. § 296. But some logicians have maintained that the predicate, though seldom quantified in expression, must always be quantified in thought--in other words, that when we say, for instance, 'All A is B,' we must mean either that 'All A is all B' or only that 'All A is some B.'