Note 319 — Chapter I
Reading edition
By a syllogism regularly expressed we mean a reasoning consisting of three propositions, which not only contain between them three and only three terms, but which are also expressed in the traditional categorical forms. Attention must be called to this because, if we introduce additional propositional forms of the kind indicated on page 146, we may have a valid reasoning with two negative premisses, which satisfies the condition of containing only three terms; for example,
No M is P,
Some M is not S,
therefore, There is something besides S and P.
It will be found that this reasoning is easily reducible to a valid syllogism in Ferison.