But while not binding it can still be cogent since it is a plausible form of
inference.
Induction can be used for ascribing general properties or general relations to
things based not on total observation of the thing, but a limited number of
observations. In other words, induction involves using particular rules, events
and things to formulate a general rule or conclusion. For example, we observe
the sun rising day after day. We can use this observation to obtain by an
induction a law that the sun rises everyday – it does so now and is likely, even
very likely, to do so in the future. In abstract form, if A1 is X, A2 is X, and A3
is X, we can argue that it is possible that each instance of A is a species of X,
that is, A1-n, all fall within the class designated by X.
Popular Illustrations
Proverbs,
and
popular sayings can incorporate or allude to inductive
reasoning in various ways. (i) Many are directly based on induction because
they express a common observation as a proposition that is universally true.
Some examples are the following. ‘A man is known by the company he keeps
(which is also expressed in the proverb that birds of a feather flock together).’
‘You cannot teach an old dog new tricks.’ ‘A rolling stone gathers no moss.’
‘A stitch in time saves nine.’ ‘Action speaks louder than words.’
‘Appearances are deceptive.’ ‘Better the devil you know than the devil you do
not know.’ ‘Boys will be boys.’ ‘Every dog has his day.’ (ii) Some paired
proverbs present two contrasting forms of inductive reasoning that could
apply to a case. “Look before you leap” should give way in some cases to the
advice that “he who hesitates is lost”. “All things come to him who sits and
waits” contrast with “none but
the brave deserves the fair”. (iii) Some
proverbs address the mechanism of induction. (a) At least three proverbs warn
against using inductive reasoning with insufficient observation. ‘All that
glistens is not gold.’ ‘One swallow does not make a summer.’ ‘Do not judge a
book by its cover.’ (b) The proverb “there is safety in numbers” gives good
advice about reasoning with induction. The more observation one makes the
more likely it is that the conclusion is true.
Finally, some proverbs incorporate a stricter form of reasoning than induction,
namely deduction. A good example is: ‘Ask no questions and hear no lies.’
Strength of Induction
Induction may be strong or weak. The stongest case is where numerous
different observations have been made of something, and in all observed
instances it has a certain property. Induction reasons that it is true or it is likely
that the thing will have the property in all unobserved instances as well. In
formal terms this can be written as:
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