ore this apple is sour." That train of
reasoning is what logicians call a syllogism, and has all its various
parts and terms,--its major premiss, its minor premiss, and its
conclusion. And, by the help of further reasoning, which, if drawn out,
would have to be exhibited in two or three other syllogisms, you arrive
at your final determination, "I will not have that apple." So that, you
see, you have, in the first place, established a law by Induction, and
upon that you have founded a Deduction, and reasoned out the special
conclusion of the particular case. Well now, suppose, having got your
law, that at some time afterwards, you are discussing the qualities
of apples with a friend: you will say to him, "It is a very curious
thing,--but I find that all hard and green apples are sour!" Your friend
says to you, "But how do you know that?" You at once reply, "Oh, because
I have tried it over and over again, and have always found them to be
so." Well, if we were talking science instead of common sense, we should
call that an Experimental Verification. And, if still opposed, you go
further, and say, "I have heard from the people in Somersetshire and
Devonshire, where a large number of apples are grown, that they have
observed the same thing. It is also found to be the case in Normandy,
and in North America. In short, I find it to be the universal experience
of mankind wherever attention has been directed to the subject."
Whereupon, your friend, unless he is a very unreasonable man, agrees
with you, and is convinced that you are quite right in the conclusion
you have drawn. He believes, although perhaps he does not know he
believes it, that the more extensive Verifications are,--that the more
frequently experiments have been made, and results of the same kind
arrived at,--that the more varied the conditions under which the same
results have been attained, the more certain is the ultimate conclusion,
and he disputes the question no further. He sees that the experiment has
been tried under all sorts of conditions, as to time, place, and people,
with the same result; and he says with you, therefore, that the law you
have laid down must be a good one, and he must believe it.

In science we do the same thing;--the philosopher exercises precisely
the same faculties, though in a much more delicate manner. In scientific
inquiry it becomes a matter of duty to expose a supposed law to every
possible kind of verification, and to take car