ho denies the validity of this kind of
reasoning process itself. Such a man cannot in fact be forced to a
contradiction in terms, but only to a contradiction, or rather an
infringement, of the fundamental maxim of ratiocination, viz. 'Whatever
has a mark, has what it is a mark of;' and, since it is only by
admitting premisses, and yet rejecting a conclusion from them, that this
axiom is infringed, consequently nothing is _necessary_ except the
connection between a conclusion and premisses.

BOOK III.

INDUCTION.

CHAPTER I.

PRELIMINARY OBSERVATIONS ON INDUCTION IN GENERAL.

As all knowledge not intuitive comes exclusively from inductions,
induction is the main topic of Logic; and yet neither have
metaphysicians analysed this operation with a view to practice, nor, on
the other hand, have discoverers in physics cared to generalise the
methods they employed.

Inferences are equally _inductive_, whether, as in science, which needs
its conclusions for record, not for instant use, they pass through the
intermediate stage of a general proposition (to which class Dr. Whewell,
without sanction from facts, or from the usage of Reid and Stewart, the
founders of modern English metaphysical terminology, limits the term
induction), or are drawn direct from particulars to a supposed parallel
case. Neither does it make any difference in the _character_ of the
induction, whether the process be experiment or ratiocination, and
whether the object be to infer a general proposition or an individual
fact. That, in the latter case, the difficulty of the practical
enquiries, e.g. of a judge or an advocate, lies chiefly in selecting
from among all approved general propositions those inductions which suit
his case (just as, even in deductive sciences, the ascertaining of the
inductions is easy, their combination to solve a problem hard) is not to
the point: the legitimacy of the inductions so selected must at all
events be tried by the same test as a new general truth in science.
Induction, then, may be treated here as though it were the operation of
discovering and proving general propositions; but this is so only
because the evidence which justifies an inference respecting one unknown
case, would justify a like inference about a whole class, and is really
only another form of the same process: because, in short, the logic of
science is the universal logic applicable to all human enquiries.

CHAPTER II.

INDUCTI