Anyone who reflects on these arguments and others like them will recognize, through clear and unequivocal reason, the falsity of these people’s claims concerning the Lord of the worlds, and that the truth lies only in what has come from the messengers.

[Responses to Another Statement by Thābit ibn Qurra]

As for his statement:

“Furthermore, this would entail change in the substance of the first cause, something the ancients turned away from.”

There are several responses to this.

[The First Argument]

For change to proceed from something unchanging must be either possible or impossible.

If it is possible, this argument is invalid. It may then be said: nothing initially proceeded from it, and then something proceeded from it without any change in it, as many speculative thinkers maintain.

If it is impossible, he may be asked: does the changing world proceed from it or not?

If it proceeds from it, the first cause must undergo change.

If it does not proceed from it, the world is either necessarily existent in itself or possibly existent.

If it is necessarily existent in itself, yet undergoes change, it follows that what is necessarily existent in itself undergoes change.

If it is possibly existent in itself, it follows that something possibly existent has come into existence without a cause necessitating its existence.

Not only do all rational people agree that this is false; its falsity is self-evident.

Moreover, anyone who allows that something possibly existent can come into existence without an agent should all the more readily allow change in what is necessarily existent. For the former entails what is nothing becoming something without an agent; how much more readily, then, should he allow it to become something through an agent that undergoes change.

[The Second Argument]

As for your statement, “This is something all the ancients turned away from,” even if