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Meaning/content/Validity/Valid/Use/use theory/Nagel: the validity of thoughts does not depend on how they are used.
However, the practice of a community cannot be beaten by objectivity: language changes - for the content of thought - as opposed to the meaning of the words, this is not true -" meaning: is contingent! - "E.g. that "and" is a word of conjunction - "Thought content: is the conjunction (not contingent).
Das letzte Wort Stuttgart 1999
Was bedeutet das alles? Stuttgart 1990
Die Grenzen der Objektivität Stuttgart 1991