and in a negative proposition may be illustrated to the eye as
follows. To say 'All A is B' may mean either that A is included in B
or that A and B are exactly co-extensive.

[Illustration]

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