Full Idea
We do not know the logical form of sentences about counterfactuals, probabilities, causal relations, belief, perception, intention, purposeful action, imperatives, optatives, or interrogatives, or the role of adverbs, adjectives or mass terms.
Gist of Idea
There is a huge range of sentences of which we do not know the logical form
Source
Donald Davidson (Truth and Meaning [1967], p.35)
Book Reference
Davidson,Donald: 'Inquiries into Truth and Interpretation (2nd ed)' [OUP 2001], p.35
A Reaction
[compressed] This is the famous 'Davidson programme', where teams of philosophers work out the logical forms for this lot, thus unravelling the logic of the world. If they are beavering away, some sort of overview should have emerged by now...