A System of Logic, Ratiocinative and Inductive (Vol. 1 of 2)
John Stuart Mill · en
Whatever be the most proper mode of expressing it, the proposition that
the course of nature is uniform, is the fundamental principle, or general
axiom, of Induction. It would yet be a great error to offer this large
generalization as any explanation of the inductive process. On the
contrary, I hold it to be itself an instance of induction, and induction
by no means of the most obvious kind. Far from being the first induction
we make, it is one of the last, or at all events one of those which are
latest in attaining strict philosophical accuracy. As a general maxim,
indeed, it has scarcely entered into the minds of any but philosophers;
nor even by them, as we shall have many opportunities of remarking, have
its extent and limits been always very justly conceived. The truth is,
that this great generalization is itself founded on prior generalizations.
The obscurer laws of nature were discovered by means of it, but the more
obvious ones must have been understood and assented to as general truths
before it was ever heard of. We should never have thought of affirming
that all phenomena take place according to general laws, if we had not
first arrived, in the case of a great multitude of phenomena, at some
knowledge of the laws themselves; which could be done no otherwise than by
induction. In what sense, then, can a principle, which is so far from
being our earliest induction, be regarded as our warrant for all the
others? In the only sense, in which (as we have already seen) the general
propositions which we place at the head of our reasonings when we throw
them into syllogisms, ever really contribute to their validity. As
Archbishop Whately remarks, every induction is a syllogism with the major
premiss suppressed; or (as I prefer expressing it) every induction may be
thrown into the form of a syllogism, by supplying a major premiss. If this
be actually done, the principle which we are now considering, that of the
uniformity of the course of nature, will appear as the ultimate major
premiss of all inductions, and will, therefore, stand to all inductions in
the relation in which, as has been shown at so much length, the major
proposition of a syllogism always stands to the conclusion; not
contributing at all to prove it, but being a necessary condition of its
being proved; since no conclusion is proved for which there cannot be
found a true major premiss.