The rule of contraposition has been investigated thoroughly by Arabic logicians. In this paper, we study the work done by Fārābā and Avicenna, the fathers of Arabic logic. Fārābā studied contraposition of universal affirmatives, discussed its four forms, and discovered a relation between one form and the conversion of negative universals. Although Fārābā and logicians before him have used contraposition only for conditionals, as well as for indefinite and universal affirmative categorical propositions, Avicenna generalized the rule to all the four Aristotelian quantified categorical propositions. However, many of his ideas on contraposition were opposed by his 12th and 13th century followers, which are to be investigated later.

中文翻译：

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法拉比和阿维森纳论对位

阿拉伯逻辑学家已经彻底研究了对位规则。在本文中，我们研究了阿拉伯逻辑之父 Fārābā 和 Avicenna 所做的工作。法拉巴研究了全称肯定的对位，讨论了它的四种形式，并发现了一种形式与否定全称的转换之间的关系。尽管法拉巴和他之前的逻辑学家只对条件句以及不定和全称肯定的绝对命题使用对位，但阿维森纳将该规则推广到所有四个亚里士多德量化的绝对命题。然而，他的许多对位思想遭到了他 12 和 13 世纪的追随者的反对，这将在以后进行研究。