love is a fallacy 逻辑学.ppt

Introduction Logic (from the Ancient Greek) has two meanings: First, it describes the use of valid reasoning in some activity; Second, it names the normative study of reasoning or a branch thereof. In the latter sense, it features most prominently in the subjects of philosophy, mathematics, and computer science. History In Europe, logic was first developed by Aristotle. Aristotelian logic became widely accepted in science and mathematics and remained in wide use in the West until the early 19th. During the High Middle Ages, logic became a main focus of philosophers, who would engage in critical logical analysis of philosophical arguments, often using variations of the methodology of scholasticism. By the 18th century, the structured approach to arguments had degenerated and fallen out of favor, as depicted in Holbergs satirical play Erasmus Montanus. The Chinese logical philosopher Gongsun Long proposed the paradox One and one cannot become two, since neither becomes two. In China, the tradition of scholarly investigation into logic, however, was repressed by the Qin dynasty following the legalist philosophy of Han Feizi. In India, innovations in the scholastic school, called Nyaya, continued from ancient times into the early 18th century. By the 16th century, it developed theories resembling modern logic. Since 1824, Indian logic attracted the attention of many Western scholars, and has had an influence on important 19th-century logicians If a, then b. From observation to a hypothesis Opposed to deductive reasoning Topics in Logic Syllogistic logic 三段论逻辑 Propositional logic (sentential logic) 命题逻辑 Predicate logic 谓词逻辑 Modal logic模态逻辑 Informal reasoning Mathematical logic数理逻辑 Philosophical logic哲学逻辑 Computational logic计算逻辑 Bivalence and the law of the excluded middle二值和排中律 Is logic empirical? Tolerating the impossible Rejection of logical truth Fallacy A fallacy is an argument that uses poor reasoning. An argument can be fallacious whether or