  But Buridan's masterwork is the Summulae de dialectica [Compendium of Dialectic], a comprehensive logic textbook which started out as a commentary on the Summulae logicales or logical compendium of the thirteenth-century dialectician, Peter of  Spain,[7]  but soon evolved into an independent work of astonishing breadth and originality. In it, Buridan redeems the older medieval tradition of Aristotelian logic through the via moderna [modern way]—i.e., the newer, terminist logic that had gradually replaced it. Because the work was accessible to master and student alike, it became extremely popular at Paris and in newly-founded universities such as Heidelberg, Prague, and Vienna.