A Class Room Logic / Deductive and Inductive, with Special Application to the Science and Art of Teaching

by George Hastings McNair

The I proposition illustrated:

1. “Some men are wise.”

2. “Some animals are vertebrates.”

3. “Some teachers are inspiring.”

The meaning of the I proposition may be represented by two circles intersecting each other:

FIG. 3.

The significant feature of the diagram is the shaded part which represents a part of the “men” circle as belonging to a part of the “wise” circle. The unshaded part of each circle is the unknown field.

(4) The Particular Negative or O Proposition.

The common symbolization of the O is “Some S is not P.” Put in statement form: Some of the subject is excluded from the whole of the predicate.Here, as in the I, the same logical import must be given to some; e. g., in the proposition, “Some men are not wise,” our knowledge is confined to the group who are not wise. Whether or not the others are wise or not-wise is unknown.