 Lorenzo Valla (c. 1406–1457) was one of the most important humanists of his time. In his Elegantiae linguae Latinae, an advanced handbook of Latin language and style, he gave the humanist program some of its most trenchant and combative formulations, bringing the study of Latin to an unprecedented level. He made numerous contributions to classical scholarship. But he also used his vast knowledge of the classical languages and their literatures as a tool to criticize a wide range of ideas, theories, and established practices. He famously exposed the Donation of Constantine—an important document justifying the papacy’s claims to temporal rule—as a forgery. He compared, for the first time, St. Jerome’s translation of the Bible with the Greek text of the New Testament, thereby laying the foundations of critical biblical scholarship. In his Repastinatio dialectice et philosophie (Re-ploughing of Dialectic and Philosophy), also known as his Dialectics or Dialectical Disputations, he attacked scholastic-Aristotelian thought from an essentially linguistic point of view, arguing that philosophy should conform to common sense and common linguistic usage. Already highly controversial in his own times, Valla’s works continue to provoke debate in modern times, which reflects broader discussions about the philosophical relevance and significance of Renaissance humanism for the development of early modern philosophy.