The Concept of Extensity of Natural Body in the Natural philosophy of Ibn Sina

The concept of extension in natural sciences and the feature of extensity of physical objects is considered self evident and presumptive by Muslim theosophers. That a physical object has dimensions of width, length, and depth is recognized by almost all theosophers. However, they have followed different procedures in describing and explaining this fact. It is most likely that the only intellectual concept common among all classic and later philosophers is the very extensity of physical objects. The issue of extensity has not been taken into deep and precise consideration and investigation due to deeming itself evident and because of its frequent adoption and recognition by philosophers. Thus, this issue has been rarely studied according to the findings of modern science or any new approach. As the article suggests, no new or different explanation has been given for the concept of dimension and extensity since the time of Ibn Sina. Benefitting directly from Ibn Sina’s discussions on extended body, the present article seeks to offer a roughly new account of the concept of extension. In addition, it tends to see this issue not belonging exclusively to the field of intellectual sciences, but as a part of modern science. Thus it takes the relation of extension to its analogous concepts in mathematics into account.