The close dependence of a physical being on its internal principles makes it clear that material and form are the causes of the whole being in an physical being. Garden pot head poster. A corporeal being depends on its prime matter and on its substantial form. for its act of being and for the specific degree in which it has the act of being. Therefore, if we take away material or form, things cease to exist, and if there is a change of ontological shape, then it becomes a different kind of being. For example, of course no animal exists independently of its body and it will no longer be itself when it loses its physical form.