This article focuses on illustrating the internal relationship between Thomas Aquinas's thoughts on being and Gilson's philosophy of art. It, on the one hand, reveals the way in which Aquinas's philosophy was inherited and adopted by Gilson on the topic of art. Through Gilson's insights on fine art and on art our understanding of the two is enriched. On the other hand, we would also indicate some other possible ways of ”being” related to art theory and thus hope to illuminate some possible direction in which Aquinas's thoughts of beauty may be developed in contemporary studies.