Causality and its branches Abstract in the Avicenna's medicine

Like philosophy, Avicenna's medicine is divided to two sections which are theory and practical. Avicenna prevents the doctors in engaging to the philosophical problems in the second section. Because it is not his busy and the doctors must cure the decease. But his theoretical medicine is based on some philosophical foundations. In this regard, in Avicenna's view, the real doctor is someone who knows the philosophy well. Upon this point, Avicenna's views in philosophy has great influence to his medicine which the most important of them is the causality and it's branches which has been discussed in philosophical books. So, the main problem of this article is to explain the role of Causality in modern medicine, comparison of Avicenna with Zakariyyā al-Rāzī, and Aristotle's views briefly in these problems, then explaining Avicenna's views in regard of the causality, four causes, homogenization, and teleological view in medicine.