 The essential principle and purpose of all knowledge in the view of all nations is the knowledge of the existence of God, may He be blessed, through whose power the encompassing sphere is moved. This was first explained by our religion in the verse “I am the Lord” [Exod. 20:2]. The second principle is His unity. This is explained in the verse “you shall have no other gods before me” [Exod. 20:3] and in the verse “Hear O Israel! The Lord is our God, the Lord is One” [Deut. 6:4]. The third principle is that He has no body, which is also known and revealed in the verse “Take therefore good heed to yourself: for you saw no manner of form” [Deut. 4:15], and also that He is not a force within a body, in the sense that nothing that happens to dark bodies can be verified of Him, which is known and evident from the verse “I the Lord have not changed” [Mal. 3:6]. It is known by every intelligent person that these beliefs are explained with firm proofs and full demonstration in the books about physics and metaphysics written by Aristotle, as is obvious to those who make the effort to study them, so that no one will reject them and deny them unless he is a denier of the first principle, which the ancient sages considered to be punishable by stoning. (Teshuvat Apikoros: 2b; cf. ʿEzer ha-Dat: 35–36)