The trash in our scholastic theology has nothing to do with the trash in Zarathustra's reveries.
Why debate original sin with Zarathustra? There was never any question of it save in St. Augustine's time. Neither Zarathustra nor any legislator of antiquity had ever heard speak of it.
If you dispute with Zarathustra, put under lock and key the old and the new Testaments which he did not know, and which one must revere without desiring to explain them.
What then should I have said to Zarathustra? My reason cannot admit two gods who fight, that is good only in a poem where Minerva quarrels with Mars. My feeble reason is much more content with a single great Being, whose essence was to make, and who has made all that nature has permitted Him, than it is satisfied with two great Beings, one of whom spoils the works of the other. Your bad principle Ahriman, has not been able to upset a single one of the astronomical and physical laws of the good principle Ormuzd; everything progresses in the heavens with the greatest regularity. Why should the wicked Ahriman have had power over this little globe of the world?
If I had been Ahriman, I should have attacked Ormuzd in his fine grand provinces of so many suns and stars. I should not have limited myself to making war on him in a little village.
There is much evil in this village: but whence have you the knowledge that this evil is not inevitable?
You are forced to admit an intelligence diffused over the universe; but (1) do you know, for instance, if this power reaches right to foreseeing the future? You have asserted it a thousand times; but you have never been able either to prove it, or to understand it. You cannot know how any being whatever sees what is not. Well, the future is not; therefore no being can see it. You are reduced to saying that He foresees it; but foreseeing is conjecturing. This is the opinion of the Socinians.
Well, a God who, according to you, conjectures, can be mistaken. In your system He is really mistaken; for if He had foreseen that His enemy would poison all His works here below, He would not have produced them; He would not have prepared for Himself the shame of being continually vanquished.
(2) Do I not do Him much more honour by saying that He has made everything by the necessity of His nature, than you do Him by raising an enemy who disfigures, who soils, who destroys all His works here below?
(3) It is not to have an unworthy idea of God to say that, having formed thousands of millions of worlds where death and evil do not dwell, it was necessary that evil and death should dwell in this world.