5.541
At first sight it appears as if there were also a different way in which one proposition could occur in another. Especially in certain propositional forms of psychology, like “A thinks, that p is the case”, or “A thinks p”, etc. Here it appears superficially as if the proposition p stood to the object A in a kind of relation. (And in modern epistemology (Russell, Moore, etc.) those propositions have been conceived in this way.)