Letter 58 — On Being (§11)

“But there is still something superior to “substance”; for we speak of certain things as possessing substance, and certain things as lacking substance. What, then, will be the term from which these things are derived? It is that to which we lately gave an inappropriate name, “that which exists.” For by using this term they will be divided into species, so that we can say: that which exists either possesses, or lacks, substance.”