Dun Scotus (John Duns the Scot) was as close as the Franciscans came to developing a man who was what Aquinas was to the Dominicans. Although the primary source of knowledge for Aquinas was material things, he said that the mind can know the existence of purely spiritual things only in so far as they are seen by the reflective mind as being the determining factors of material things. Thus all of his proofs for the existence of God begin with physical phenomena. Scotus rejected this idea. He said that the human mind is an intellectual power so it is capable of knowing all that is intelligible. The range of the human mind in this life might be limited, but in the next life the mind can know spiritual realities directly. The basic object of the human mind, he said, is being as such. Otherwise metaphysics would not be possible. Those who believed that the basic object of the human mind was material entities could not prove the existence of a transcendent God, but only of a God who was the highest being within the universe.

Siding with Avicenna, he said that God is not the subject matter of metaphysics. That would be like the botanist attempting to prove the existence of plants. The subject matter of metaphysics is being as being. In this he readily admitted that he was returning to Aristotle. Being is not a thing. It is a universal concept that applies equally to the finite and the infinite, to spiritual as well as material entities. Since it is the most abstract of all concepts it is considered prior to all others, it is opposed only to non-being.

Considering the above it is obvious that the human mind is capable of knowing God on its own. However, he said that in its present condition the human mind is dependent on sense impressions. As a result it can only know God either inferentially or through revelation. Before we can discuss God we must know what God is. And we cannot apply Maimonides negatives, all of our inferences must be positive. We cannot assert the existence of non-being. The minimum concept of God that can be known inferentially, according to Scotus, is determined from the possibility of the existence of finite things. Since factual propositions concerning finite things are necessarily true while at the same time the existence of finite things is contingent. It must be true that there must exist an infinite through which the finite things come to be. That infinite must be God and if finite things exist then God necessarily exists.

it is important for our understanding of the beginning of the renaissance that in the end he must return to the idea that knowledge is derived either from experience or from inference from experience.


By the fourteenth century new translations of Aristotle's logical works had been made available and a great deal of discussion turned to the use of logic and the meanings of logical terms. Schisms in the church had turned violent. Waves of the black death took the lives of a third of the population of Europe. William of Ockham was a part of that. Excommunicated from the church he joined the struggle between pope and emperor with Emperor Ludwig of Bavaria and finally died of the black death. The important points of Ockham's philosophy for our study deal with the separation of philosophy and theology. His logical treatises deal with the use of words to denote logical relations. But for our purposes his metaphysics has more immediate importance. His description of metaphysics is complex. God, he said, is the primary subject of metaphysics, but concerning predication being is primary. We cannot conceive of God except in terms of being and its attributes. We can say of both God and creatures that they are, that they are not nothing. But the opposition between being and nothing for God is different than it is for creatures. Since we have no intuitive knowledge of God in this life we cannot have a concept which expresses the divine reality. Our ideas of God are dependant on our ideas of finite things and their qualities. To have any kind of valid idea of God we must begin with our concepts of finite things and then strip away all finite limitations. He rejected the concept of possible essences, believing that essence must be of something that exists. Thus shelving several previous proofs of the existence of God and paving the way for the forthcoming revival of extreme nominalism.

The world consists of substances and their accidents and the existence of any of them does not entail the existence of any other. The result is that we can prove the existence of God only if we mean by god that which is most noble and perfect. It cannot be proved that the God of Christian faith exists, that must be accepted through faith. The principle that Ockham is most famous for, Ockham's razor, became one of the underlying motives for his reevaluation of philosophy and theology. The aim of the principle was to reduce the multiplication of concepts whereby something could be known To accomplish this he divided science into two fields, real science, which dealt with real things we find in the sensual world, and rational science which dealt with terms which do not stand immediately for real things. His object was to make relations simply relationships between things and ideas and not entities in themselves. Real individual things are the sole existences, he said. If something can be explained in terms of two concepts there is no need to add a third.

As we leave the medieval world, we leave a world where philosophy has been dominated by theologians and where truth as that obtained through revelation from scripture has been the dominant theme. This problem of truth is without question a major theme of philosophy. Truth is not something that can be proved logically unless by truth you mean only the inner consistency of a set of logical propositions. Truth must always rest on faith. This is true no matter what that faith is in.