Before Aristotle, some of the topics in the science of logic had appeared in a scattered form in the words of the great Zeno, Plato, Socrates, and some Sophists. However, Aristotle was the first scholar to compile theoretical logic and classify its topics into related parts and chapters in a book. Based on his own epistemological principles, he propounded predicative logic. From among his most important logical ideas, we can refer to predicative reasoning and categorical syllogism.
After Aristotle, another school of logic entitled Stoic-Megarian was developed in Greece by other logicians such as Philo, Diodorus, Megari, Zeno, and Chrysippus. Unlike Aristotelian logic, this new school dealt with conditional logic. Megarians’ detection of compound conditional syllogisms and Stoics’ detection of other compound syllogisms, such as conjunctive and disjunctive propositions and the forms of connected and disconnected syllogisms, created conditional logic. Therefore, the logical legacy of Greece consists of two Aristotelian and Stoic-Megarian Schools.
Muslim Peripatetics, who were well-aware of Greeks’ logical legacy, diverted from the method of Greek philosophers in devising the science of logic. In addition to reducing some logical problems, such as the problem of categories, the differentiated discussion of poetry, rhetoric, and dialectics, as well as some changes in other areas such as conversion, and descriptive definitions, they played an influential role in the development and advancement of the science of logic. In this paper, some of these changes have been discussed.