Ockham and Efficient Causality

OCKHAM AND EFFICIENT CAUSALITY SOME four hundred years before David Hume wrote his Inquiry Concerning Human Understanding a fourteenth century philosopher and theologian had already encountered amazingly similar difficulties with the validity of the causal proposition. William of Ockham had consistently attacked the arguments for the existence of God which he found in the works of his predecessors. The underlying basis for that attack is to be found in the theory of causality which Ockham held. It is the purpose of this article to explain that theory and to investigate the reasons which led Ockham to accept it. It will be evident, I think, that these reasons not only anticipate the difficulties of Hume concerning causality, but that they are at the root of many modern attacks on the validity of the causal proposition. In the second place Ockham's theory of causality makes it quite clear what happens to our knowledge of the metaphysical structure of reality, when the human intellect is restricted to an intuition of singular, sensible existents. St. Thomas had left no doubt about man's capacity to know the existing, sensible thing. He, however, had also made it quite clear that the mind could come to a certain knowledge of principles and relationships , which could not be directly intuited, but which were necessary for the existing sensible thing to be and to function the way it did. Thus he was able to assert the reality of such principles of being and operation. As a result, the universe of Aquinas is one composed, not only of things, but of real principles of things which necessarily co-exist to make the thing what it is and which explain, not only the whatness of the thing, but also the reason for its presence in the realm of limited existents. Such a universe can be validly approached from the viewpoint of philosophy and can be given a philosophically valid explanation. 106 OCKHAM AND EFFICIENT CAUSALITY 107 Such, as will be made clear from what follows, is not the case with William of Ockham. Reality for him is no such composite structure. There are no realities which compose the real. There are just singulars, unique and uncomposed. The mind can and does abstract various aspects or formalities from these singulars, but such formalities cannot possibly be conceived as having any reality of their own outside of the abstracting intellect. For Ockham there is only one way to get at existence, and that is in an intuition of the sensibly existing singular. Any further intellectual activity prescinds from existence. Such an intellect can never again assert the extra-mental reality of any of its formulations or abstractions. It is not surprising, then, that in examining the question of the possibility of proving the existence of God, Ockham had decisively rejected the validity of the ontological argument. If one could prove that God did exist, there was only one way to do it. That was to start with that world of experience which was the primum cognitum and from that world build an argument which would prove conclusively that such a world was unintelligible, unless there existed a God. It would seem that, if ever there was a man capable of arguing from the data of experience to the existence of a first cause of such data, that man was William of Ockham. With his theory of intuition of the singular existent, he had placed himself in direct contact with the existing world. He insisted on the contingency of that world and on its complete dependence on God. Did not that contingency demand necessity somewhere for its ultimate explanation? And was not causality a fact in that world of facts with which Ockham was concerned? And if the mind intuits the existing, contingent singular, does it not see in that contingent singular the evidence that marks it indelibly as an effect? It is a bit startling, then, that Ockham not only answers in the negative but proceeds to attack the traditional arguments which had been used to prove the existence of God. It is impossible to understand that attack, unless one first understands Ockham's teaching on the nature of causality. In...