This is the epistemological problem, and it was a very fundamental one, but of course – as behind all problems in philosophy and theology – it is always the problem of God which is decisive, and so I now go to the doctrine of God in medieval thinking, and I come again partly to these three men of the 13th century.
The medieval idea of God has three levels: 1) The first and fundamental level is the idea of God as primum esse, the first being, or prima causa, the first cause. By “cause” here is meant not as “cause and effect,” as we have it in the realm of finitude – the word “prima,” “first,” means not the first according to time, but the ground of all causes, so that the term “cause” is here used more symbolically than literally. It is the creative ground in everything, creatrix universa1ium substantia, the creative substance of everything that is. This is the first statement about God. He is the Ground of Being, as I like to express it, or being itself, or the first cause – all these terms point to the same meaning.
2) This substance cannot be understood in terms of the inorganic realm – for instance, as an inorganic substance like fire or water, as the old physicists did – nor in the biological situation, as a life process, but it must be understood as intellect.
The first quality of the Ground of Being is intellect. Intellect doesn’t mean intelligence, but it means the point in which God is for Himself subject and object at the same time; or, as it was carried through, God knowing Himself and knowing the world as that which He is not. The Ground of Being, in other words – the “creative substance” – is a bearer of meaning. The world – this is the consequence – is meaningful, can be understood in words which have meaning. The logos, the word, can grasp it. In order to understand reality, we must presuppose that reality is understandable; and reality is understandable because the Divine ground has the character of intellect. Only because the Divine intellect the ground of everything, is knowledge possible.
3) The third characteristic, which comes from the Christian Augustinian tradition – while the intellect comes from the Greek Aristotelian tradition: God is will. Will, of course, if applied to God and the world, is not the psychological function which we know in ourselves, but it is the dynamic ground of everything. It is the productive power of the Ground of Being. This will has the nature of love – in good Augustinian tradition. The creative substance of the world has meaning and has love – is intellect and will, symbolically speaking. And as with respect to knowing we said that God knows Himself, so we must now say that God wills or loves Himself as the absolute good, indeed as the ultimate aim of everything. And He loves the creatures in giving them, in a graded way. the good of which He is the ultimate Ground. Therefore they all are longing for Him, and He is for them the object of that love which everything has and every being has, the love toward that in which it sees its ultimate good. Now this is the medieval idea of God. This God is not called a person. The word “person” is never applied to it in the Middle Ages. for two reasons: 1) because the Trinitarian “faces” or “countenances” are called personae: the Father is persona, the Son is persona. and the Spirit is persona. But persona here means more a special characteristic of the Divine ground, expressing itself in an independent hypostasis. Therefore we can say the term persona has been applied to God only in the 19th century, when God was made into a person, and the greatness of the classical idea of God was destroyed by this kind of speaking. Of course this structure. including being, intellect and will. is analogous to our experience of our own being, and if we call ourselves “person” we must call God also “Person.” But this is something quite different from calling God “a Person” First of all. He is being itself. He is the Ground of Being in everything. The personal side is expressed in intellect and will. and their unity. But to speak about a person would have been absolutely heretical for the Middle Ages; it would have been Unitarian heresy for them. because this would exclude that God has three personae. namely. expressions of His being.
Now about the relationship of intellect and will in God. there the same fight was going on as about the epistemological problem. For the Thomistic tradition, intellect is characteristic of God and man. Thomas argues that only because man is intellect is he able to be distinguished from an animal. An animal would be a man in the moment in which it was able to put purposes intellectually before the will.