That, however, is not the point at issue. If what is intended is that whatever depends on something intrinsic to itself is thereby contingent in itself, such a claim is inadmissible; indeed, its falsehood is self-evident. For its dependence on what is included within itself is no greater than its dependence on its very self. Once it is granted that it exists of itself—meaning that it is not in need of anything external to it—this does not entail that its self has no need of its self, and by the same token it does not entail that it has no need of what is contained in the very notion of itself.
When it is said, “It is in need of itself,” the statement has two possible senses. The first is that it needs to bring itself into existence and the like; this is intrinsically impossible, for nothing can be the efficient cause of its own being—this is known intuitively. The second is that its self subsists only by itself, cannot dispense with itself, and that the existence of its self without its self is impossible; this is correct and unavoidable.
Likewise, when it is said, “It is in need of what is included within itself—whether one calls that an attribute, a part, or anything else,” we inquire: do you mean that this part acts as its efficient cause or something similar? Such a notion is impossibly false, and no rational person would affirm it. If, however, you mean that it cannot exist unless that part exists, and that its existence without it is impossible, then the dependence posited here is less than the dependence already admitted with respect to its very self. For if its self cannot subsist except by itself, then—of necessity—it cannot subsist except together with what is included within itself. If the former is a necessary matter free of objection, the latter is, a fortiori, even more so. And just as the assumption that its self could dispense with its self entails its non-existence, so too the assumption that it could exist without what is included in the very meaning of itself—something inseparable from it—truly entails its non-existence.