Last Friday I tried to wrap up the discussion of ‘On the Principles of Nature’. We got a little bit bogged down with the distinction between per se vs. per accidens causes. But if you always keep in mind that per accidens is best translated as ‘coincidental’, then you should be able to make sense of the distinction, especially if you carefully re-read this explanation (http://faculty.fordham.edu/klima/medphil/per%20se%20vs%20per%20accidens.htm). The important point in connection with this distinction is that when we talk about something as the per se or  per accidens  cause of something else, what matters is not only what we are talking about as the cause, but also how we are describing it, namely, whether with reference to its causally relevant feature, that quality on account of which it is precisely the cause of its effect, or not. Consider the projector hanging from the ceiling in the classroom causing the light on the screen. If we are describing this thing as the projector or illuminator that illuminates the illuminated thing (the screen), then we are describing it as the per se cause of that light, because it is the cause of that light precisely insofar as it is an illuminator, a light-source. But if we are just describing the same thing as the thing hanging from the ceiling, and say that the thing hanging from the ceiling causes that light, then we name the per accidens cause of that light, because its hanging from the ceiling is causally irrelevant for its activity as a light source. The thing does not cause light because it is hanging from the ceiling (it could do the same if it were sitting on a desk), but precisely because it is an illuminator, something that emits light.

Now, if we are considering the per se causes of one and the same effect, we can also observe that some of these are actual causes, others merely potential. A potential cause is one that does not actually operate but it can produce its effect, say, the projector when it is turned off.  An actual cause, on the other hand, is one that actually operates, such as the projector when it is turned on. The actual cause of an effect is such that its actual working is necessary for sustaining the existence of the effect: the screen is illuminated only as long as the projector illuminates it. If you turn it off, the effect (the screen’s being illuminated) is gone at once.

The importance of all this is that a per se  actual cause has to be in actuality in respect of what it actualizes in the effect. Since the per se cause is what provides that energy that sustains the actuality of the effect, it already has to have that energy in itself. But then, since nothing can be both in actuality and in potentiality in the same respect (it would be impossible for the projector to be merely potentially emitting light, as when it is turned off, and actually, as when it is turned on, at the same time; it is either on or off), nothing can be the per se cause of itself. Thus, if we have an ultimate effect (such as the light on the screen) whose existence is sustained by a per se, actual cause, then we can ask about the cause of the activity of the cause itself: what is the cause of that? (What accounts for the working of the projector when it is on?) The cause of the ultimate effect cannot per se cause itself to operate, thus there must be a further cause, which is the cause of the operation of the cause of the ultimate effect (such as the electricity powering the projector). But if the activity of that cause is not self-explanatory, then we should seek the per se cause of that too. (What powers the wires that provide the electricity for the projector?) And the same questioning can be repeated concerning the next cause and the next, etc. The question that immediately arises from this procedure is whether in this series of per se actual causes we have to go to infinity, or whether there is a First Cause whose activity accounts for every other cause down the chain of causes and whose activity is not caused by the activity of anything else.

There is yet another important distinction in the text that can help us answer this question, namely, that between proximate and remote causes (which, as we’ll see, corresponds to the distinction between less and more universal causes). A per se cause further down the chain, closer to the ultimate effect is a proximate cause. In our example, the projector in our class room is the actual, proximate, particular cause of the light on that screen, when it is on. A more remote cause is one further up the chain. In our example, the electrified wires powering the projector are the proximate causes of the working of the projector, and so they are the remote causes of the light. The transformer house on campus powering the wires is a more remote cause of the light, and the power plant powering the transformer is an even more remote cause. We should also observe, however, that as we are moving to more remote causes, those are also more universal causes, causing the operation of an ever greater range of more proximate causes producing an ever greater range of ultimate effects. (The transformer on campus powers not only the wires powering the projector, but also the wires powering the lights, computers, etc., and the power plant powers not only the campus transformer, but the entire grid of which the transformer is a part.) But then, as we are moving up the chain of causes we are reaching ever more universal ones. Thus, there must be a First Cause, if there is a most universal aspect of all effects that are sustained by it. But the most universal aspect of all effects is that they all exist. Thus, if there is a First Cause, then this cause must be the per se, actual, universal cause of all being, which has to be in actuality in all possible respects at once.

Now this is the philosophical idea of a First (Efficient) Cause, originally coming from Aristotle’s Physics and Metaphysics, that served for medieval theologians to articulate the religious idea of an absolutely perfect, omnipotent, omniscient and benevolent God, the Creator of the Universe, who not only created everything at the beginning of time, but also continuously sustains the existence of His creation, without whose continuous creative activity this entire creation would fall into nothing.

On Tuesday, we are going to discuss Boethius’ text assigned on the “new and improved” syllabus (with the help of the required lecture note: http://faculty.fordham.edu/klima/lectures.htm#Boethius), so as to understand how this philosophical idea of a First Cause is related to the religious idea of an absolutely good God, who is the source of all goodness in the universe. And, of course, in this connection we shall also raise the question of how it is possible at all that there is any evil in the creation of such a good God, which is the big theological “Problem of Evil”.