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Thinking / Prior: must not have the form of sentences - even if we think in sentence form, we do not think sets - e.g. we fear dogs, no sentences - fear that p does not lead to fear a sentence which means p - "I have my broken leg" does not mean:" I have broken what is usually called "my leg" in German" - my relation to the sentence is parasitic to the relation to the leg.
Thinking / general / Prior: one can certainly think of something general: E.g. that there are cases of infidelity.
Objects of thought Oxford 1971
Arthur N. Prior
Papers on Time and Tense 2nd Edition Oxford 2003