"We picture facts to ourselves." (2.1)
"My fundamental idea is that the 'logical constants' are not representatives; that there can be no representatives of the logic of facts." (4.0312)
"Philosophy aims at the logical clarification of thoughts. Philosophy is not a body of doctrine but an activity." (4.112)
"Logic must look after itself." (5.473)
"My propositions serve as elucidations in the following way: anyone who understands me eventually recognizes them as nonsensical, when he has used them—as steps—to climb up beyond them. (He must, so to speak, throw away the ladder after he has climbed up it.)" (6.54)
