Ibn Khaldun on Alchemy and Astrology

He set aside Avicenna's proof that metals cannot change species. His “most reliable argument” is that no human can know every stage of nature.

Ibn Khaldūn, Muqaddimah ch. VI §32, tr. Franz Rosenthal (1958), vol. III.

Two sections of Ibn Khaldūn's Muqaddimah (1377) refuting astrology and denying that alchemy works.

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Ibn Khaldūn; trans. Franz Rosenthal, The Muqaddimah: An Introduction to History, vol. III (Bollingen Series XLIII), 1958, ch. VI §32, 'A denial of the effectiveness of alchemy'His own proof of alchemy's impossibility, from the impossibility of complete knowledge of nature's stages, set against Avicenna's argument from the species of metals; alchemy pursued by those unable to earn their living.
It is the most reliable argument I know of.