  Zabarella identifies therefore the basic difference between arts and sciences. Science deals with what already exists, but art is concerned with creation. The subject-matter of a science is immutable, but the subject-matter of an art is the formation of things as yet non-existent, but which can be made by human being. The contemplative philosopher is not interested in initiating anything, but rather wants to comprehend and arrange the forms of existing, eternal things. Moreover, the ultimate purpose of the contemplative science is the pursuit of knowledge for its own sake, but in the productive arts the end-result is an actual product (Mikkeli 1997, pp. 212–213).