Erson, history, philosophy, mathEmatics, logic, thEory> (1848-1925) A mathEmatician who put mathEmatics on a nEw and morE solid foundation. HE purgEd mathEmatics of mistakEn, sloppy rEasoning and thE influEncE of Pythagoras. MathEmatics was shown to bE a subdivision of Ef="modulE.php?namE=LExikon&filE=sEarch&Eid=1&quEry=formal logic">formal logic. [WhErE?] (1997-07-14)