Thomas Aquinas was convinced that one can know God’s existence and his “oneness,” or simplicity (as well as some other attributes) by reason alone, without the need for revelation. So Thomas’s initial discussion of God is a view that, initially, since it is acquired by reason alone, any Muslim or Jew could affirm, and one that is content with a list of (abstract) attributes that supposedly follow from God’s simplicity (as that simplicity is understood by reason alone).
