An introductory text-book of logic - Mellone, Sydney - Rare Books at ...

234 THE GENERAL NATURE OF INDUCTION.
known to us. A well-grounded conviction that there
are no negative instances, even in the absence of com
plete assurance, may afford a very high degree of proba
bility. This appears to have been the view of Aristotle
(Topics, viii. 8); and as Aristotle suggests, if any one
objects to a generalisation held on such grounds,
it rests
with the objector to find a negative instance.
What modern Inductive Logic inquires into is, how
we establish a reliable general statement, one which
goes beyond the range of our particular experience, and
yet is more than
"
probable." How are we justified
in
concluding from one or more cases known to us, a law
for all cases of the same kind ? How, in short, can we
establish a Law of Nature ? To this question Aristotle
paid comparatively little attention ; what he says about
it is contained in the doctrines of the Enthymeme and
the Example.
3. The Aristotelian Enthymeme is of great logical
it covers the elementary forms of what
significance ;
later writers have called Induction. And in his treat
ment of it, Aristotle marks some of the stages by which
we pass from guess-work towards scientific knowledge.
In one place he speaks of it as
"
a rhetorical form of
the syllogism," useful for persuasion and for concealing
fallacies (Rhetoric, i. 2) ; but it is much more than this.
An enthymeme is "an argument from probabilities or
signs
"
ovv eVrl
(An. Prior., ii. 27: evOv/Jifj^a fjuev
ef elicoTCOV r) oyfAel&v). The word
is derived, not directly from eV and Ovfjios, but
from evQvfjLeio-Qcu, to reflect upon, or hold as probable.
By eifcos, the "probable," Aristotle means the rough
generalisations of ordinary practical experience (e/jurei-
pia), such as are embodied in proverbs, &c. Enthy-
"
memes ef eltcoTwv, from "probabilities of this kind, are