In the Islamic philosophy, common sense is conceived as a cognitive faculty that perceives sensual, conventional, and intuitive concepts. This article deals with the issue of common sense ontologically and epistemologically.Muslim philosophers, since Ibn Sina, have adopted an ontologically reductionist approach to common sense by suggesting the unity of nafs and by reducing its faculties to mere concepts and names. In this article, common sense is epistemologically investigated. The question of whether common sense provides knowledge by presence or be presentation is examined first, and then Ibn Sina’s idea is explained with regard to the issue of correspondence. At the end, the authors study the problem of substantial motion in Ibn Sina to answer a challenge to his theory concerning lack of any pivot for absolute knowledge. The conclusion is some sort of epistemology, called gradational epistemology.