FIGURE III.
§ 654.
B is A. B is not A.
B is C. B is C.
.'. Some C is A. .'. Some C is not A.
We produce instances of C being A by showing that C and A meet, at all events partially, in B. Thus if we wish to produce an instance of the compatibility of great learning with original powers of thought, we might say
Sir William Hamilton was an original thinker.
Sir William Hamilton was a man of great learning.
.'. Some men of great learning are original thinkers.
Or we might urge an exception to the supposed rule about Scotchmen being deficient in humour under the same figure, thus—
Sir Walter Scott was not deficient in humour.
Sir Walter Scott was a Scotchman.
.'. Some Scotchmen are not deficient in humour.
FIGURE IV.
§ 655.
All A is B, No A is B.
All B is C. All B is C.
.'. Some C is A .'.Some C is not A.