Note 315 — Chapter I
Reading edition
On examination it will be found that the only syllogism rejected by this rule and not also rejected directly or indirectly by the preceding rule is the following:—All P is M, All M is S, therefore, Some S is not P. In the technical language explained in the following chapter, this is AAO in figure 4. So far, therefore, as the first three figures are concerned, we are left with a single rule, namely, a rule of distribution, which may be stated in either of the alternative forms given above.