This art, which I call the art of persuading, and which, properly speaking, is simply the process of perfect methodical proofs, consists of three ess… - Blaise Pascal

" "

This art, which I call the art of persuading, and which, properly speaking, is simply the process of perfect methodical proofs, consists of three essential parts: of defining the terms of which we should avail ourselves by clear definitions, of proposing principles of evident axioms to prove the thing in question; and of always mentally substituting in the demonstrations the definition in the place of the thing defined.