ABSTRACT
The student who has no special distaste for dealing with a few easy symbols will find no difficulty with the Eductions. In the light of what has just been said about contradictory terms, it is also possible to give alternative formulations to the Laws of Contradiction and Excluded Middle. The formula for the Law of Contradiction, as given in the preceding chapter, is S cannot both be P and not be P, and the formula for the Law of Excluded Middle is S must either be P or not be P. The converse of a given proposition is a proposition implied by it, but having its subject for predicate, and its predicate for subject. The only way of obtaining new eductions is by applying the processes of obversion and conversion alternately, each to the result of the other.
