Ali Ebne Abbas Ahvazi, the Pioneer of Applying the Theory of "Haft Iqlim" in Persian Medicine

The importance of the effect of geographical location on people's mezaj and its role in the prevention and treatment of diseases is an essential aspect of the subject of climate, which is one of the six essential principles. This study aimed to find the origin of the theory of "Haft Iqlim" and identify the pioneer who applied it in Persian medicine.

The present study applied the library-documentary method and followed a descriptive-analytical approach.

This study examined first-hand religious, geographical, and medical sources of Greek and Islamic territory to first discover the origin of the theory of dividing "Rub-e-maskun" into "Haft Iqlim" and then find the pioneer who applied this theory in Persian medicine.

The first trace of the theory of dividing the world into four parts was found in an Akkadian writing which belongs to the third millennium BC, and the first signs of dividing the "Rub-e-maskun" of the world into "Haft Iqlim" were discovered in Avesta. These theories found their way to Greece and were developed in the works of Ptolemy. Afterward, during the translation movement, they returned to their initial origin, the Middle East. Masoudi's books were the turning point of the combination of these two theories in Islamic Iran, and this combinatorial theory has progressed after him. However, they were first applied in medicine about the same time or shortly after Masoudi by Ali ibn Abbas of Ahwaz. For the first time, Ahwazi considered mezaj of the fourth Iqlim in the manufacture of medicine in his book "Kamel Al-Sina'a Al-Tabiya" for Persian people; therefore, he can be considered the pioneer of applying this theory in Persian medicine.