 Similar to most other Neoplatonists, Israeli accepted the Aristotelian definition of a substance as a something of which something is said or predicated—and not something which is said of something else. Within a substance, matter is the substratum for the form which determines its being as substance. Further matter can be either particular or general and universal, and if particular “it is the substratum for a special form which constitutes the essence of a particular species…” (Isaac Israeli, p. 86)