Miftah Dar al-SaCadah
Ibn Qayyim Al-Jawziyya was also an astronomer and chemist, and a critic of alchemy and astrology. In his Miftah Dar al-SaCadah, he used empirical arguments in astronomy and chemistry in order to refute the practice of alchemy and astrology along with the theories associated with them, such as divination and the transmutation of metals.
He recognized that the stars are much larger than the planets, and thus argued:
"And if you astrologers answer that it is precisely because of this distance and smallness that their influences are negligible, then why is it that you claim a great influence for the smallest heavenly body, Mercury?
Why is it that you have given an influence to al-Ra's and al-Dhanab, which are two imaginary points ascending and descending nodes?"
He also recognized the Milky Way galaxy as "a myriad of tiny stars packed together in the sphere of the fixed stars" and thus argued that "it is certainly impossible to have knowledge of their influences.