This too is mistaken, for the relevant proofs require that the two be treated alike, even supposing that a causal agent could lack power and choice. How much more so, then, when that is impossible?

That an effect or product of an action can only be such after prior nonexistence is one of the self-evident truths generally agreed upon by rational people, past and present. All of them say:

“Whatever is an effect whose existence and nonexistence are both possible must have a beginning, preceded by nonexistence.”

Among those who stated this were Aristotle and his followers; even Ibn Sīnā and others like him explicitly affirmed it.

Yet Ibn Sīnā contradicted this by claiming that the celestial sphere is eternal and beginningless, while also being contingent, admitting both existence and nonexistence. This contradicts what he himself explicitly stated, as did his authorities and all other rational people. It was among the views for which Ibn Rushd the grandson criticized him, explaining that it contradicted the explicit statements of Aristotle and the other philosophers, and that no one before him had held it.

Aristotle did not divide existence into necessary and contingent, nor did he say that the First necessitates the world’s existence by its very essence. Rather, this is the position of Ibn Sīnā and others like him. Although it is closer to the truth, despite its unsoundness and internal contradictions, it is not the position of his predecessors. Rather, Aristotle and his followers held that the celestial sphere needs the First only because it moves in order to resemble it, not because the First is its efficient cause.

The substance of Aristotle’s position and that of his followers is that whatever necessarily exists is