Full Idea
Sommers took the 'predicable' terms of any language to come in logically charged pairs. Examples might be red/nonred, massive/massless, tied/untied, in the house/not in the house. The idea that terms can be negated was essential for such pairing.
Gist of Idea
'Predicable' terms come in charged pairs, with one the negation of the other
Source
report of Fred Sommers (Intellectual Autobiography [2005]) by George Engelbretsen - Trees, Terms and Truth 2
Book Reference
'The Old New Logic', ed/tr. Oderberg,David S. [MIT 2005], p.26
A Reaction
If, as Rumfitt says, we learn affirmation and negation as a single linguistic operation, this would fit well with it, though Rumfitt doubtless (as a fan of classical logic) prefers to negation sentences.
Related Ideas
Idea 18903 Sommers promotes the old idea that negation basically refers to terms [Sommers, by Engelbretsen]
Idea 18906 Negating a predicate term and denying its unnegated version are quite different [Engelbretsen]