Note 370 — Chapter III

Lambert gave the following dictum de exemplo for figure 3:—“Two terms which contain a common part partly agree, or if one contains a part which the other does not, they partly differ.” This maxim is open to exception. The proposition “If one term contains a part which another does not, they partly differ” applied to MeP, MaS, would appear to justify PoS just as much as SoP, or else to yield an alternative between these two. Mr Johnson gives a single formula for figure 3, namely, “A statement may be applied to part of a class, if it applies wholly [or at least partly] to a set of objects that are at least partly [or wholly] included in that class.” This is correct, but perhaps not very easy to grasp.