St. Thomas Aquinas' Five Proofs for God’s Existence
To answer the question concerning God’s existence, St. Thomas Aquinas presented five
ways or proofs in his most notable work, the Summa Theologica. This is also called
"Aquinas' Five Proofs for God's Existence". These five arguments draw proof or evidence
from man’s experience with the world, which are noticeably influenced by Aristotle and
his concept of the four causes.
The first argument that Aquinas formulated is the argument from motion. After
observing objects in motion, Aquinas was convinced that whatever is currently in
motion were once at rest but had changed states when it was moved by something else.
This mover was something once at rest as well but was also moved by something else.
This line of thought would go on and on until it forms an almost infinite series of
concurrent events where the objects are both movers and moved. But if this series of
events needed something to begin the movement, then, it is logical to assume that at
the very beginning of this infinite series is the first mover, which starts the
movement. Aquinas describes this first mover as the “unmoved mover,” a label which is
quite similar to Aristotle’s “prime mover.” As we can see, both see this mover as one
that is not caused or moved by anything other than itself. And for Aquinas, this is God.
The second argument is the argument from causation, which builds upon Aristotle’s
concept of the efficient cause. The main idea here is that every object, action, or event,
according to Aristotle, has an efficient cause or an entity or event responsible for its
creation or change. Just like how a baby finds their efficient cause in their parents and
their parents in their own parents and so on and so forth, Aquinas uses these examples
of dependent relationships to show that every person or object in the world depends on
a creator (efficient cause) and that this creator also has its own creator, and this new
creator also has its own efficient cause. This cycle, much like the argument from motion,
can go on infinitely but, according to Aquinas, it should not be so since in the first place
the series would not have begun.
It is then logical to assume that at the very beginning, there is the existence of a “First
Maker” or an “Uncaused Cause,” which, as the name suggests, is the efficient cause that
is not caused by others or anything but itself. This “Uncaused Cause” is, of course,
attributed by Aquinas to the Christian God.
The third argument is the argument from contingency which necessitates the
distinction between “necessary” and “possible” beings. “Possible” beings, simply put,
are beings that can be created and corrupted or are beings that can exist and not exist.
To answer the question concerning God’s existence, St. Thomas Aquinas presented five
ways or proofs in his most notable work, the Summa Theologica. This is also called
"Aquinas' Five Proofs for God's Existence". These five arguments draw proof or evidence
from man’s experience with the world, which are noticeably influenced by Aristotle and
his concept of the four causes.
The first argument that Aquinas formulated is the argument from motion. After
observing objects in motion, Aquinas was convinced that whatever is currently in
motion were once at rest but had changed states when it was moved by something else.
This mover was something once at rest as well but was also moved by something else.
This line of thought would go on and on until it forms an almost infinite series of
concurrent events where the objects are both movers and moved. But if this series of
events needed something to begin the movement, then, it is logical to assume that at
the very beginning of this infinite series is the first mover, which starts the
movement. Aquinas describes this first mover as the “unmoved mover,” a label which is
quite similar to Aristotle’s “prime mover.” As we can see, both see this mover as one
that is not caused or moved by anything other than itself. And for Aquinas, this is God.
The second argument is the argument from causation, which builds upon Aristotle’s
concept of the efficient cause. The main idea here is that every object, action, or event,
according to Aristotle, has an efficient cause or an entity or event responsible for its
creation or change. Just like how a baby finds their efficient cause in their parents and
their parents in their own parents and so on and so forth, Aquinas uses these examples
of dependent relationships to show that every person or object in the world depends on
a creator (efficient cause) and that this creator also has its own creator, and this new
creator also has its own efficient cause. This cycle, much like the argument from motion,
can go on infinitely but, according to Aquinas, it should not be so since in the first place
the series would not have begun.
It is then logical to assume that at the very beginning, there is the existence of a “First
Maker” or an “Uncaused Cause,” which, as the name suggests, is the efficient cause that
is not caused by others or anything but itself. This “Uncaused Cause” is, of course,
attributed by Aquinas to the Christian God.
The third argument is the argument from contingency which necessitates the
distinction between “necessary” and “possible” beings. “Possible” beings, simply put,
are beings that can be created and corrupted or are beings that can exist and not exist.
