Some philosophers, who failed to take notice of this distinction, maintained that the matter which exists under a substantial form is an _incomplete being_, and an _incomplete substance_. The expression is not correct. For, if the matter which lies under the substantial form were an incomplete being, it would be the office of the form to complete it. Now, the substantial form can have no such office; for the form always inchoates what the matter completes. It is always the term that completes the act, whilst the act actuates the term by giving it the first being. Hence the matter which lies under its substantial form is not an incomplete entity. Nor is it an entity destined to complete the form; for, if the term which completes a form were a being, such a term would be a real subject, and thus the form terminated to it would not be strictly substantial, as it would not give it the first being. Moreover, the matter and the substantial form constitute _one_ primitive essence, in which it is impossible to admit a multiplicity of entitative constituents; and therefore, since the substantial form, which is a formal source of being, is evidently an entitative constituent, it follows that the matter lying under it has no entity of its own, but is merely clothed with the entity of its form. But, true though it is that the matter lying under a substantial form has no entity of its own, it is, however, a _real_ term, as we have already intimated; hence it may be called a _reality_. And since _reality_ and _entity_ are commonly used as synonymous, we may admit that the formed matter is an entity, adjectively, not substantively, just as we admit that ivory is _a sphere_ when it lies under a spherical form. Nevertheless the ivory, to speak more properly, should be said _to have sphericity_ rather than _to be a sphere_; for, though it is the subject of sphericity, it is not spherical of its own nature. In the same manner, a body vivified by a soul is called _living_; but, properly speaking, it should be styled _having life_, because life is not a property of the body as such, but it springs from the presence of the soul in the body. The like is to be said of the being of the matter as actuated by the substantial form. It is from the form alone that such a matter has its first being; and therefore such a matter has only a borrowed being, and is a _real potency_, not a real entity. Such is, we believe, the true interpretation of S. Augustine’s phrase: “nothing-something” and “being non-being”--_Nihil aliquid, et est non est_.