Keelefilosoofia raamat
and her husband is very smart too"; "Paul was a philosopher and his wife
wasn't very smart either."
Here, as in many cases, a good way to investigate the nature of these dif-
ferent kinds of implications is to ask about the penalty or sanction that ensues
when an implicatum is false. When S1 entails S2 and S2 is false, the penalty is
that S1 is false. When S1 semantically presupposes S2 and S2 is false, then S1 is
sent ignominiously to zip. When someone utters S1, thereby conversationally
implicating S2 , and the conveyed meaning or invited inference S2 is false, then
the penalty is that, even if S1 is true, the speaker's utterance is misleading. If
S1 conventionally implicates S2 and S2 is false, then S1 is misworded, even if
not false.
A further type of "pragmatic presupposition" not already mentioned here
might be called "illocutionary implication": The performing of a speech act