ectypal.net

Although the knowledge of God is one and simple intrinsically no less than his essence, yet it can be considered in different ways extrinsically as to the objects. But it is commonly distinguished by theologians into the knowledge of simple intelligence [scientam simplicis intelligentiae] (or natural and indefinite) and the knowledge of vision [scientia visionis] (or free and definite). The former is the knowledge of things merely possible and is therefore called indefinite because nothing on either hand is determined concerning them by God. The latter is the knowledge of future things and is called definite because future things are determined by the sure will of God.