Absurd or Impossible, reduction to the
Absurd or Impossible, reduction to the. This is a mode of establishing a
position by showing that its contradictory would overthrow that which
has been already established or admitted. If the conclusion for which I
contend be not true, its contradictory must be so in virtue of a
fundamental law in logic.
Make of this contradictory a premiss, instead
of one already proved or granted. A conclusion will be the result
contradictory of the latter. But that by hypothesis is true, therefore
the substituted one must be false, and its contradictory, the position
contended for, must be true.
This kind of reasoning is sometimes used by Euclid; and in logic, so
long as reduction to the first figure was held necessary to the full
establishment of a syllogism, it was applied for that purpose to the
moods baroco and bocardo.