Some people have claimed that Saint Thomas Aquinas argues for the existence of God from the premise,
“everything has a cause.” This is emphatically not the case.
Aquinas does NOT believe that everything has a cause. Indeed, he argues for the exact opposite
conclusion: God exists and he is not caused. He is the only absolutely “uncaused cause.”
In this video, we conclude our three-part examination of the “Second Way”—the
way of efficient causality—through which Aquinas demonstrates the existence of God.
In our first video on Aquinas’s Second Way, we introduced this famous argument
for God’s existence. And we noted that the Second Way BEGINS with ordinary experience
and CONCLUDES that God exists by arguing “from the nature of efficient causality.”
In our previous video (the second video), we examined the nature of causality itself. We
saw that an efficient cause is a profoundly ACTIVE type of cause. An efficient cause is
THAT WHICH BRINGS SOMETHING INTO BEING or IN SOME WAY ALTERS A BEING THAT ALREADY EXISTS.
Moreover, through our example of a sculptor and a marble bust, we concluded that every
efficient cause produces an effect, and that every effect must have a cause. There
is no such thing as an effect without a cause. And no effect can “cause” itself.
Thus, we concluded, that every time we encounter an
effect we know—with absolute certitude—that there must be a cause behind the effect.
Now, in this third (and final) video on Aquinas’s Second Way,
we apply what we have considered thus far to this second proof for the existence of God.
Through sensation and experience, we can recognize that there is no cause in the
universe that is not also, at least in some way, effected by something else. There is not
a single autonomous cause in all of the cosmos. Everything depends upon other things—at least in
some way. Everything in the world in which we live is “a caused cause” of some sort.
But, in Aquinas’s Second Way, he observes that it is not possible for a series of
caused causes “to go on to infinity.” There must exist one FIRST and HIGHEST
efficient cause that is not, itself, the effect of another efficient cause.
In other words, there must—necessarily and conclusively—be a single and first
cause that is absolutely UN-caused—that stands outside of the universe but yet
holds the universe (and everything contained by the universe) in
being. And this first efficient cause, Aquinas concludes, is God.
In order to understand Aquinas’s argument, we must recognize what kind of causal series he
is talking about here. When Aquinas says that it is impossible to have an infinite series
of efficient causes, he does NOT have in mind an ACCIDENTALLY subordinated series of causes.
Causes in an accidental series exercise SEQUENTIAL causality (much like a long
series of dominoes tiles in which the fall of a preceding tile causes
the fall of the following tile—one after another, individually and sequentially).
In contrast, Aquinas’s argument concerns an ESSENTIALLY ORDERED series of efficient
causes. In an essential series, the causality of “caused” (or “INTERMEDIATE”) cause is DEPENDENT
UPON and SIMULTANEOUS WITH the causality of the PRIMARY or FIRST EFFICIENT CAUSE.
To illustrate this essential type of series,
let us imagine a musician playing beautiful music on a piano. In this scenario,
the musician represents the FIRST EFFICIENT CAUSE of the music that we hear.
The piano’s components (its keys, its strings,
and its hammers) are also causes of the piano music—but they are CAUSED
CAUSES (they are causes of the music because they are moved by the musician).
The music itself, of course, is the EFFECT of both the musician and of the piano’s
various components. But we also recognize that the piano’s components only serve as
intermediate causes of the music BECAUSE of the primary causality
of the musician and only WHILE the musician continues to play.
Thus, when we hear live music being played on a piano,
we are sensing the EFFECTS of efficient causes. Moreover,
we know that every effect must have a cause—there are no such things as effects without a cause.
Therefore, when we hear live music, we conclude with certainty that there must exist both a piano
and a musician—intermediate causes (a piano) and a first efficient cause (the musician).
Similarly, the Second Way reasons to God’s existence from the fact that “an order of
efficient causality” imbues all of contingent reality. Causality is something that we encounter,
recognize, and can even understand through everyday human experience.
Through our five senses, we are aware, FIRST, that things actually exist; and,
SECONDLY, that actually existing things really undergo changes of
various sorts. Things come in to existence from others.
Things undergo modifications in their existence because of others. All of
this reflects the dynamics of efficient causality. All human persons recognize
that this causality informs and profoundly shapes all of the reality we experience.
Therefore, because the dynamics of causality in our everyday experience are certain,
we can conclude WITH CERTAINTY that there must be a FIRST efficient cause. (GOD.)
And this first cause must be unique because it, necessarily, causes not only the CAUSALITY
of the other, INTERMEDIATE causes, but this first efficient cause must be the cause even
of the very BEING and EXISTENCE of all other causes in the very foundations of their being.
The emphasis in Aquinas’s argument here is not upon intermediate
causes INDIVIDUALLY or SEPARATELY considered. His emphasis, rather,
is upon the SERIES OF CAUSES ITSELF. The Second Way argues that there must be a
FIRST EFFICIENT CAUSE in order for there to be a series of efficient causes at all.
In brief, a reality in which ONLY CAUSED causes exist is absolutely impossible.
Impossible. All caused causes—like those that we encounter at virtually every moment of our
entire life—presuppose and depend upon an absolutely uncaused cause. There must
exist an absolutely first being, an existent who causally upholds
all other things in their being and in their own respective active causality.
If we were to summarize the essence of Aquinas’s Second Way in a sentence, perhaps we could do
so like this: Nothing would exist here and now unless there were—here and now—a first, uncaused
cause who sustains all other things in their being, their existence, and their causal power.
In other words, if there were no first efficient cause, literally nothing else would be.
Because other things are,
then there must—necessarily—exist a first efficient, uncaused cause.
And, as Aquinas says, this uncaused cause—this
first efficient cause—is what everyone refers to as “God.”
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