In books on logic, no variables ought to occur, but only the general propositions which justify the use of variables. It follows that the so-called definitions of logic are not definitions, but only schemes of definitions, & instead of these we ought to put general propositions; & similarly the so-called primitive ideas (Urzeichen) of logic are not primitive ideas, but the schemes of them. The mistaken idea that there are things called facts or complexes & relations easily leads to the opinion that there must be a relation of questioning to the facts, & then the question arises whether a relation can hold between an arbitrary number of things, since a fact can follow from arbitrary cases. It is a fact that the proposition which e.g. expresses that q follows from p & p ⊃ q is this: p.p ⊃ q. ⊃ _p.q.q.