The Cosmological Argument of Aquinas
Thomas Aquinas attempts to prove the existence of god in five ways. Three of the
five arguments Aquinas uses are based on motion, efficient cause, and necessity. In each
argument he uses the concept of infinite regress and the principle of sufficient reason to
claim that each argument must lead back to a diving being. One counter argument to
Aquinas is that made by Paul Edwards, in his criticism Edwards attempts to prove that
each of the three arguments are not sufficient enough to prove the existence of a diving
being. The claims made by Thomas Aquinas are not strong arguments based on any new
insight or original thought, but rather an attempt to prove that since we do not know
where we came from it must have been God, these arguments will be shown week in the
argument for God as the creator of life.
To fully understand the arguments made by Aquinas, we must first understand the
two core concepts he claims leads each argument to the conclusion of a diving being, The
principle of sufficient reason and the idea of an infinite regress.
The principle of sufficient reason is the idea that nothing happens without a
reason, or that everything in existence has a sufficient explanation. This is based on the
observation of our world and everything within it, everything from the order of the
universe down to the functions of plants and animals. Based on our observation nothing
happens without a reason or an explanation, there are no brute facts, therefore we are led
to believe that the universe and everything within it must have a reason for existing.
According to Aquinas, the reason or explanation for our existence then must be god.
(Class notes, handout 2)
An infinite regress means that a cause of an action would go back infinitely.
There would be no end to how far back a cause would go, this means there would then be
no beginning for that cause either. Aquinas argues that an infinite regress must be
avoided. According to our observations of the world, everything must have a beginning.
Because of this, an infinite regress is impossible and must be avoided, to avoid an infinite
regress there must be a first cause, God. (Class notes, handout 2)
Aquinas then applies these two core concepts to his each of his arguments,
coming to a conclusion that a diving being must exist. The first argument of Aquinas is
based on motion. Anything in motion would have to be put into motion by something that
is already in motion; nothing can be put into motion by itself. This is well understood law
of physics. This action would continue infinitely, but to avoid an infinite regress, as
Aquinas claims we must, and to satisfy the principle of sufficient reason, there would
have to be a first mover. This prime mover would have to be God. (class notes, handout 2)
The second argument made by Aquinas is based on efficient cause. Again, based
on all our observations, every cause has an effect and every effect has a cause. It is
impossible for something be the cause of itself. This cause and effect will then go back
infinitely, but again we must avoid this infinite regress and satisfy the principle of
sufficient reason. To do this we must come to the conclusion that there must be an
uncaused cause; this would have to be God. (Class notes, handout 2)
The third argument of Aquinas is that of necessity. Our existence is contingent
upon something existing before us. Because out of nothing comes nothing, in order to
satisfy the principle of sufficient reason, there must have always been a necessary being.
This being would then have to be god. (Class notes, handout 2)
The conclusion that Aquinas comes to in each of his arguments, that god must be
the first cause, is challenged by Paul Edwards in his counter argument. Edwards argues
against the two core ideas that Aquinas uses to come to his conclusion, the principle of
sufficient reason and the infinite regress, Edwards then attempts to disprove the causal
argument made by Aquinas.
Edwards claims that the principle of sufficient reason, that everything must have
an explanation, does not prove that there must be a God. Aquinas uses the principle of
sufficient reason to claim that there cannot be any brute facts, but Edwards then replies
that God being the answer to this problem would make him a brute fact. God would then
be no more of a logical explanation for how we are here than something like atoms or
energy. (Class notes, handout 2)
The second bases for each of Aquinas’s arguments, which claim an infinite
regress is impossible and must be avoided, is then challenged by Edwards. According to
Edwards, infinite regress in not impossible as previously claimed. We can see that it is
possible based on the fact that numbers can regress infinitely. (Class notes, handout 2)
Disproving the principle of sufficient reason and showing that an infinite regress
is in fact possible, Edwards has effectively diminished the strength of Aquinas’s
argument, but he does not end at that. He says that even if the argument based on cause is
valid, it would not necessarily mean that there is a divine being. The argument would not
prove that there was a single first cause or that the first cause is still in existence. It also
would definitely not prove that the first cause must posses all the attributes that we think
a divine being must possess. Edwards then presents the idea that there could be many
sustainers such as heat, gravity, or atoms. (Class notes, handout 2)
Edwards makes a more logical, more convincing argument, he effectively breaks
down each part of Aquinas’s argument and proves the arguments weaknesses. He shows
that the foundation of the argument is questionable and therefore the argument looses its
credibility.
Based on both arguments, the use of the principle of sufficient reason is not found
convincing enough to prove that there is a God. It is not used effectively enough in the
argument because no person could effectively use it. From our understanding everything
does have an explanation, but just understanding this is true and knowing the
explanations for everything are far different. Just because we know something must have
a reason, this does not allow us to assign explanations as we see fit.
Aquinas is arguing that in order to provide a sufficient explanation, it proves the
need for a primary cause. This is not true, it could be strong reason to believe in the
possibility of a divine being, but it is not proof there must be a God. With the lack of
evidence on both sides of the argument, at this point the explanations are nothing more
than speculation.
The claim that an infinite regress is impossible and must be avoided is based on
the assumption that we have a better understanding of the universe than we actually have.
Aquinas claims that based on our observations everything has a beginning, but this is
based on limited observation made over a relatively short period of time, and without a
complete understanding of nature.
We can make observations of relatively short life cycles, but we can’t even
observe human life back to its origin. We are far from understanding the beginning and
ending of the universe. Everything happens within time and space, but we do not even
understand fully what time is and how it is tied in with space, so to make a claim of
certainty based on the notion that we understand any principle of the beginning of time is
absurd and impossible to back up. There may very well be no beginning; infinite regress
may in fact be the only possibility.
The arguments of motion, cause, and necessity are tied together with the above.
Our knowledge is limited, so our explanations are also limited. Our lack of evidence also
means we can not convincingly deny the existence of God. As we continue to gain
knowledge, our arguments will become stronger. We may prove without a doubt that a
divine being was never necessary for creation. We may instead discover, like the answer
from an unsolvable brainteaser being revealed to us, that the mind of God was before us
all along. Whatever we find, the current argument of Aquinas is to easily disputed and
not sufficient to prove the existence of God.