ABSTRACT
The problem of the determination of the various types of immediate inference falls into two parts. In the first part are considered the various inferences which may be drawn from a given proposition in terms, or in respect, of another proposition having the same subject and the same predicate as the given proposition, but differing from it in respect of quality, or of quantity. The second part deals with inferences which may be drawn from a given proposition involving certain other subjects and predicates than those of the given proposition. The assumptions in questions are included among the so-called Laws of Thought, and are known as the Law of Contradiction and the Law of Excluded Middle. These are fundamental assumptions on which all consistent thinking rests; all apparent exceptions rest on misunderstandings, or on quibbles. With the aid of these Laws of Thought we may consider the opposition of propositions.
