And if they say:
“The kind of temporally originated events is a necessary concomitant of the body of the celestial sphere and the soul; these two are necessary concomitants of the intellect, which is itself a necessary concomitant of that which is necessary in itself,”
we reply: Its essence therefore necessarily entails the kind of temporally originated events, whether through an intermediary or without one. Yet nothing temporally originated can proceed from an eternal essence that necessarily entails its effect, either through an intermediary or without one, whether what originates is a kind or an individual instance. For a temporally originated kind cannot coexist with that essence from eternity, just as a temporally originated individual cannot coexist with it from eternity. A temporally originated kind comes into existence only successively, whereas whatever coexists with that essence from eternity is eternal with it and does not come into existence successively.
Thus, temporally originated events cannot proceed from a complete cause that necessarily entails either their kind, with its members coexisting with one another, or any individual event among them. It is therefore untenable that the world proceeds from a cause that necessitates its existence, just as it is untenable that the world is necessary in itself. This is what we sought to establish.
A further clarification is that whatever is eternal necessarily entails either the eternity of the cause that necessitates its existence or its own necessity in itself. For whatever is eternal is either necessary in itself or necessary through another. A contingent thing with no cause necessitating its existence cannot exist, let alone be eternal; this is self-evident and agreed upon by all rational people. If it is necessary through another, the cause necessitating its existence must be eternal; this is self-evident and agreed upon by all rational people. If it is necessary through another, the cause necessitating its existence must be eternal, and it cannot necessitate its existence unless the conditions for doing so are also eternal. Thus, neither the cause necessitating the existence of what is eternal nor any condition of that necessitation can be temporally originated, for the necessitating cause associated with an efficacious agent cannot come after what it necessitates