The idea of someone who sits down "to think about something" in order to find out what he did not yet know, is just as slanted as the opposite about intuitions that just come to us. Thinking originates in the work on a subject (Sache) and in formulations. they take care of its passive elements. Said exaggeratedly: I do not think, and that is what thinking really amounts to. The pencil or the pen which someone holds in his hand while thinking are not inappropriate sensible signs for this situation. It is said that Simmel and Husserl did this. Husserl apparently could not think in any other way as by writing, just as some writers get their best ideas by writing. Such instrument, which do not even to be pracically employed, remind us that we should not think without focus, but [always] about something. That is why texts that must be interpretd or criticized support the objectivity of thinking in an inestimable way. [Band 10: Kulturkritik und Gesellschaft I/II: Anmerkungen zum philosophischen Denken. Theoder W. Adorno: Gesammelte Schriften, S. 8400 (vgl. GS 10.2, S. 607)]
This is not unrelated to Luhmann's conviction that real thought must be connected to what has already been said (be anschlussfähig).