„The possibility of being able to carry out truth-operations in this propositional calculus includes the possibility of recognizing internal relations between propositions (cf. TLP 6.124): whoever has mastered this calculus knows, for example, that the proposition "p ∧ q" automatically (internally, autarkically) affirms the propositions "¬(¬p ∧ q)", "¬(p ∧ ¬q)", "p", "q", etc., that these can be inferred from it; accordingly, anyone can invent tautologies or tinker with a table of the internal relations between propositions, or "give in advance a description of all 'true' logical propositions" (TLP 6.125) – tautologies are required only for the unpractised, i.e."