Notion. When he uses the words notio and notiones in philosophical
discussion, Cicero tells us that he does so as the Latin equivalent for
the Greek ἔννοῑα and
πρόληψις, the latter of course not in the sense
of anticipation. We may consider notion therefore as nearly synonymous
with the result of conception. A notion is a concept. The word, however,
is often used in a somewhat vague range of meaning.
In conversation it is often synonymous with opinion. "He has many
strange notions." This is quite outside any philosophical use. Like idea
too, it is often still further diverted from its true meaning by being
employed for liking, chiefly, however, in negative declarations. "I
have no notion of waiting for him a whole afternoon."