Note 368 — Chapter III

The dictum for figure 2, sometimes called the dictum de diverso, is expressed in the above form by Mansel (Aldrich, p. 86). It was given by Lambert in the form, “If one term is contained in, and another excluded from, a third term, they are mutually excluded.” This is at least expressed loosely, since it would appear to warrant a universal conclusion, if any conclusion at all, in Festino and Baroco. Bailey (Theory of Reasoning, p. 71) gives the following pair of maxims for figure 2,—“When the whole of a class possess a certain attribute, whatever does not possess the attribute does not belong to the class. When the whole of a class is excluded from the possession of an attribute, whatever possesses the attribute does not belong to the class.”