Let’s Review: Cause
In the previous post, we discussed that there are two kinds of series of causes and effects. An accidentally ordered series is a series temporally sequenced. An example might be to consider the case of a father begetting a son, who in turn begets another. If the father dies after begetting the son, the son can still beget a son of his own for once in existence the son has the power to do this all by himself. He doesn’t need his father to remain in existence for him to be able to sire a son. Imagine a long line of such fathers begetting sons who in turn beget sons of their own. In every case, the son has the power to beget a son of his own even if his father goes out of existence. Each member of the series, each “causer” of a son, is independent of the previous members of the series. This series is accidentally ordered in that it is not essential to the continuation of the series that any earlier member of it remain in existence. We observe such accidentally ordered series all around us. A cue ball rolls across the table striking a billiard ball causing it to roll across the tables as well. Or the example of the long line of dominoes used in the previous post. An accidentally ordered series of causes and effects is one in which the continuation of the series is independent of the existence and/or continued action of earlier members in the series.
Accidentally ordered series extend backwards in time, and theoretically can extend back forever. Because each member of such a series has its causal powers independently of the existence or action of previous members in the series, there is nothing about the actions of the members existing here and now that requires that we trace it back to some first member existing in the past. Even if there was a first cause of an accidentally ordered series, I cannot prove its existence here and now from the actions/changes in the current members of the series. In fact, the series would continue even if the first mover no longer existed, or existed only for a brief moment – just long enough to get the series going. Thus, there is no way to philosophically prove that such a series ever had a beginning or a first member.
An essentially ordered series of causes and effects is a series where each cause is simultaneous to each effect. Think of a hand which is pushing a stone by means of a stick. The motion of the stone only happens as long as the stick is moving it, and the stick is moving only as long as the hand is pushing it. At every moment in which the stone is moving, the stick is moving and the hand is pushing. The stone and the stick as well, only move because and insofar as the hand moves them. Strictly speaking, it is the hand alone which is doing the moving of the stone. The stick is merely an instrument by which the hand accomplishes this. This series is essentially ordered because the latter members in the series have no independent motion of their own and derive the fact of their motion and their ability to move from the first member in the series. Without the earlier members in the series, and specifically without the first member, the series would not continue.
Essentially ordered series do not extend backwards in time but rather “downward” in the present moment since they are series in which each member depends simultaneously on other members which simultaneously depend in turn on yet other members, and so on. In essentially ordered series, the latter members of the series have no independent causal power of their own but are mere instruments of a first member. If the last member in the series exists, e.g., the moving stone, the series cannot, even in theory, extend back infinitely. In an essentially ordered series, the actualization of one potential depends on the simultaneous actualization of another potential, which depends on the simultaneous actualization of another, which depends on the simultaneous actualization of another, which …. While the series may extend a long way, it cannot extend infinitely for an essentially ordered causal series exists here and now (not backwards in time) and by its very nature must have a first member. There must be a first member that provides the causal power being transmitted throughout the series.
Now in order for there not to be an infinite regress, there must be a first member. This first member must itself be unmoved and unchangeable. For if it was moving or changing, it would be going from potential to actual and there would need to be something outside it actualizing its potential in which case it would no longer be the first member.
In the first way, we see that Aquinas identifies this first member, the First Mover, as God.
To Be or Not To Be
In his second way of proving the existence of God, Aquinas begins with the simple observation that things exist. In order for a thing to change, it must exist. In order for the universe to undergo change, it obviously must exist. Specifically, it must continue in existence from moment to moment. So why does it do so? Why does anything keep existing? What keeps the universe going?
Before we get into the “meat” of Aquinas second way, let’s take a moment to provide some background.
The tree outside my window exists. It has being. Two principles explain its being, i.e., essence and existence. For the actually existing tree, indeed for any thing that actually exists in the world, both essence and existence are necessary. Essence and existence are distinct from each other. This distinction is real.
Essence is the “what” of a thing. It is the quiddity of the thing, that which is known about it by the forming of a concept. In this way it is a formal principle, because it is abstracted by the intellect. It is a universal principle making many material beings to be of the same kind (e.g., horses, animals, men, fish, rocks, etc.).
But essence, “what a thing is”, is completely distinct from a thing’s existing, “that it is”. The essence of a thing does not indicate anything about whether that thing actually exists. The essence of a horse that exists in the physical world and the essence of a horse that doesn’t (an imaginary horse) are the same – they both have “horse-ness”. A thing’s existing is totally different from what kind of a thing it is. Therefore there must be something about really existing things that accounts for this. This is their existence. Existence then is that which makes essences “to be”, to exercise the act of existing. Aquinas identified the act of existing with the Latin term “esse”, to be.
The relationship of essence and esse is likened by analogy to that relationship between form and matter. Form determines and actualizes some part of matter. Similarly, esse actualizes the potency of a thing’s essence. This similarity is only analogous. Form can be separated from matter by abstraction. However, the esse and essence of a thing are not separable in real beings. Esse is logically prior to all other actuality because a thing cannot be in a certain way unless it first simply “is”. Because of this logical priority of existence, Aquinas calls esse “the most formal of all.” “It is the actuality of all acts” since a thing “is” in virtue of esse (existence) and “acts are of supposits” of what “is”.
The Second Way – Argument from Existence
Aquinas bases his second way of proving God’s existence on the observable fact that the universe does indeed exist.
“The second way is from the nature of the efficient cause. In the world of sense we find there is an order of efficient causes. There is no case known (neither is it, indeed, possible) in which a thing is found to be the efficient cause of itself; for so it would be prior to itself, which is impossible. Now in efficient causes it is not possible to go on to infinity, because in all efficient causes following in order, the first is the cause of the intermediate cause, and the intermediate is the cause of the ultimate cause, whether the intermediate cause be several, or only one. Now to take away the cause is to take away the effect. Therefore, if there be no first cause among efficient causes, there will be no ultimate, nor any intermediate cause. But if in efficient causes it is possible to go on to infinity, there will be no first efficient cause, neither will there be an ultimate effect, nor any intermediate efficient causes; all of which is plainly false. Therefore it is necessary to admit a first efficient cause, to which everyone gives the name of God.”
As mentioned above, the question that Aquinas is posing is not whether the Universe has a beginning or not. He is not asking a question about what got things started or even about how long the Universe has been in existence. Rather taking the observable fact that the universe exists in such a way that its existence persists from one moment to the next, why does it do so? What keeps the universe going? What keeps the universe in existence?
Is there something in the natures of the physical things that exist in the universe that allows them to persist? The answer is quite simply no. Consider the nature or essence of any thing in the physical universe. Consider the essence of a human being. For argument’s sake, let’s agree with Aristotle that the essence of a human being is to be a rational animal. Does knowing that tell us anything about whether people really exist? Does it tell you whether Barak Obama, Aristotle, or Clark Kent exists? We know Barak Obama exists because we have seen him on television or met him in person. Aristotle doesn’t exist anymore. Clark Kent never existed outside the Superman comics and movies. So there is nothing about the essence of a thing that entails whether or not the thing really exists.
The second way is from the nature of the efficient cause. In the world of sense we find there is an order of efficient causes. There is no case known (neither is it, indeed, possible) in which a thing is found to be the efficient cause of itself; for so it would be prior to itself, which is impossible.
As described above, the essence of a thing and the existence of a thing are distinct. There is nothing in the essence that necessitates existence. Something then needs to put essence and existence together for a thing to be real. That “something” cannot be the thing itself for to give itself existence a thing would have to exist already. So nothing can cause itself. Whatever comes into existence – whatever must have existence added to its essence in order for it to be real must be caused by another.
Aquinas is not saying that everything must have a cause. What is being said is that only what does not have existence on its own must have a cause, and since it cannot have existence on its own, this cause must be something other than itself.
To recap then, the essence of everything in the physical universe is distinct from its existence. Each of these things must be caused by something outside itself. From this, it becomes clear that the universe as a whole must have a cause outside itself.
As in the case of change, here we can identify two kinds of causal series: accidentally ordered and essentially ordered. Remember that accidentally ordered series are temporally sequenced, extending back in time. But again, Aquinas is not concerned with what events in the past led to what exists in the here and now. Rather, Aquinas is asking what is it that is keeping the things that exist, here and now, in existence here and now. What is sustaining the existence here and now?
Let’s return to an example we used above – the example of fathers begetting sons. Your father beget you but he is not what is sustaining you in being here and now. Remember that this represents an accidentally ordered series – your existence here and now is independent of your father’s existence or non-existence here and now. My own father died 18 years ago. Yet, I still exist.
No, what’s sustaining your existence is something like the current state of the cells of your body, which in turn are sustained by what’s going on at the molecular level, and the atomic level, along with gravitation, the weak and strong forces, and so forth – all of which whose essence is distinct from their existence and thus need a cause outside themselves. In short, we have another essentially ordered causal series which as we previously showed must end in a first cause.
In fact considering the universe as a whole, its elements, down to the smallest detail, consists of elements whose essence is distinct from their existence and thus cannot account for their own being from moment to moment. The universe as a whole must be sustained in being here and now by a cause outside itself, a First Cause, which simultaneously upholds the entire series.
Now in efficient causes it is not possible to go on to infinity, because in all efficient causes following in order, the first is the cause of the intermediate cause, and the intermediate is the cause of the ultimate cause, whether the intermediate cause be several, or only one. Now to take away the cause is to take away the effect. Therefore, if there be no first cause among efficient causes, there will be no ultimate, nor any intermediate cause. But if in efficient causes it is possible to go on to infinity, there will be no first efficient cause, neither will there be an ultimate effect, nor any intermediate efficient causes; all of which is plainly false. Therefore it is necessary to admit a first efficient cause
This First Cause cannot itself be composed of essence and existence. For if it had both essence and existence, it would require something outside of itself to explain its own existence and thus would no longer be a first cause. The essence/existence distinction does not apply then to the First Cause. Rather the First Cause is pure existence, pure being – not a being, strictly speaking, but Being Itself, fully actualized.
Aquinas upon demonstrating the necessity of the First Cause further describes it as that “ to which everyone gives the name of God”.
