"Aquinas believes that human beings (even in our earthly condition here below) can have knowledge, scientific knowledge of God's existence, as well as knowledge that he has such attributes as simplicity, eternità, immateriality, immutability, and the line. In Summa Theologiae Aquinas sets out his famous Five Ways or five proofs of God's existence: in Summa Contra Gentiles he sets out the proof from motion in much greater detail; and in each case he follows these alleged demonstrations with alleged demonstrations that God possesses the attributes just mentioned. So natural knowledge of God is possible. [...] So most of those who believe in God do so on faith. Fundamentally, for Aquinas, to accept a proposition on faith is to accept it on God's authority; faith is a manner of "believing God" (ST, IIa, IIae, ii, 2) "for that which is above reason we believe only because God has revealed it" (SCG, I, 9)."