According to Farabi, there are 3 types of reasoning; rhetorical, dialectical, and demonstrative.

Farabi describes rhetorical reasoning to lay in the premise of figurative language and similes. It is persuasive reasoning originating from the syllogistic arts of rhetoric, poetry and linguistics, and is commonly employed for use on the multitudes.

Dialectical reasoning uses the premise of commonly held opinions often based on shared experiences. It too is persuasive, but stems from theology and jurisprudence, and is used on the multitudes.

Demonstrative reasoning uses the premises of first principles to logically conclude and verify something; the logic commonly starts from scratch. It is originated and embedded in the art of philosophy and is employed by the ‘select’, or those who contain on active intellect.

Farabi uses these three types of reasoning to explain the difference between theology, jurisprudence and philosophy in the following manner:

Philosophy uses first principles to form laws for society in order to keep the multitudes happy. However, the universally practical and theoretical matters that philosophy attains to, is built upon first principles. Since not all the multitudes are capable of understanding the premises of first principles, religion is employed to demonstrate these laws in more figurative language, thus, demonstrative reason arises laws for the masses.

Philosophy then employs religion to convey the messages of philosophy to the masses in rhetorical language, employing symbolism and figurative language so the multitudes can understand. This is important because it is persuasive reasoning used to have the multitudes understand the underlying philosophy behind the religion.

Through religion comes theology, which uses religion to convey to the masses universal theoretical and practical matters. Thus, theology is rhetorical, using persuasive messages shrouded in figurative language to push philosophies point across.

When the founder of the religion does not openly convey all that is required for complete udnersanding, jurisprudence arises, whereby dialectical reasoning is employed to use commonly help opinions to fill in the gaps where the religions founder left holes. Thus, jurisprudence uses dialectical reasoning to determine universally practical matters.

This explanation put forth by Farabi is not entirely convincing since he limits the scope of theology, jurisprudence and philosophy. Farabi’s detailed explanation of these 3 in relation to the 3 modes of reasoning seem to infer that philosophy can never use figurative language, or jurisprudence can never determine legal standings based on first principles. The inference suggests that upon transgressing into another mode of reasoning, philosophy for example, may become theology or jurisprudence, or vice versa. This limits the capability of what philosophy can attain and through what rationalization means it can attain them. Same with theology and jurisprudence. Thus, by limiting the scope of each he is limiting the boundaries of each practice, and, while well thought out, does not appear to be wholly convincing.