 Traditional logic texts (and the first edition of the Logic) methodically discuss how to reduce complex syllogisms to simple ones. Later editions of the Logic abbreviate this “pedantry” in favor of a general principle for reducing complex syllogisms, or actually, to evaluate them directly without an explicit reduction. The general principle is that the conclusion must be contained in the premises. The principle is applied by making a characteristic Cartesian move. One is to come up with a “better known” proposition from which the conclusion follows—the “containing” proposition (III.10,163). Then one needs another proposition that shows that the conclusion is indeed contained in the containing proposition—this is the “applicative” proposition. Recall that the comprehension of a term contains all the attributes constituting it while the extension contains the objects that have those attributes.