on, then forty-five years of age, in the
_Edinburgh_ (1833). There can be no doubt that it awakened Mill's
interest in the subject. A society formed for the discussion of
philosophical questions, and called the Speculative Society, met at
Grote's house in 1825, and for some years following. Of this society
young Mill was a member, and their continuous topic in 1827 was Logic,
Whately's treatise being used as a sort of text-book.

It is remarkable that Mill's review of Whately, the outcome of these
discussions, says very little about Induction. At that stage Mill's
chief concern seems to have been to uphold the usefulness of Deductive
Logic, and he even goes so far as to scoff at its eighteenth century
detractors and their ambition to supersede it with a system of
Induction. The most striking feature of the article is the brilliant
defence of the Syllogism as an analysis of arguments to which I have
already referred. He does not deny that an Inductive Logic might be
useful as a supplement, but apparently he had not then formed the
design of supplying such a supplement. When, however, that design
seriously entered his mind, consequent upon the felt need of a method
for social investigations, it was Whately's conception of Induction
that he fell back upon. Historically viewed, his System of Logic was
an attempt to connect the practical conditions of proof set forth in
Herschel's discourse with the theoretic view of Induction propounded
in Whately's. The tag by which he sought to attach the new material
to the old system was the Inductive Enthymeme of the Schoolmen as
interpreted by Whately.

Whately's interpretation--or misinterpretation--of this Enthymeme,
and the conception of Induction underlying it, since it became Mill's
ruling conception of Induction, and virtually the formative principle
of his system, deserves particular attention.

"This, that and the other horned animal, ox, sheep, goat,
ruminate; _therefore_, all horned animals ruminate."

The traditional view of this Enthymeme I have given in my chapter on
Formal Induction (p. 238). It is that a Minor Premiss is suppressed:
"This, that and the other constitute the whole class". This is the
form of the Minor in Aristotle's Inductive Syllogism.

But, Whately argued, how do we know that this, that and the other--the
individuals we have examined--constitute the whole class? Do we not
assume that what belongs to the individuals examined belongs to the