“A tautology's truth is certain, a proposition's possible, a contradiction's impossible.”

“Most of the propositions and questions to be found in philosophical works are not false but nonsensical.”

“There is a truth in Schopenhauer’s view that philosophy is an organism, and that a book on philosophy, with a beginning and end, is a sort of contradiction. ... In philosophy matters are not simple enough for us to say ‘Let’s get a rough idea’, for we do not know the country except by knowing the connections between the roads.”

“We cannot therefore say in logic: This and this there is in the world, that there is not.For that would apparently presuppose that we exclude certain possibilities, and this cannot be the case since otherwise logic must get outside the limits of the world: that is, if it could consider these limits from the other side also.”

“Der Zweck der Philosophie ist die logische Klärung der Gedanken.Die Philosophie ist keine Lehre, sondern eine Tätigkeit.Ein philosophisches Werk besteht wesentlich aus Erläuterungen.Das Resultat der Philosophie sind nicht »philosophische Sätze«, sondern das Klarwerden von Sätzen.Die Philosophie soll die Gedanken, die sonst, gleichsam, trübe und verschwommen sind, klar machen und scharf abgrenzen.4.112The object of philosophy is the logical clarification of thoughts.Philosophy is not a theory but an activity.A philosophical work consists essentially of elucidations.The result of philosophy is not a number of "philosophical propositions", but to make propositions clear.Philosophy should make clear and delimit sharply the thoughts which otherwise are, as it were, opaque and blurred.”

“It is not humanly possible to gather immediately from it what the logic of language is. Language disguises thought.”

“The agreement or disagreement or its sense with reality constitutes its truth or falsity.”