Aquinas: argument from motion, contingency, and causation

Who was Thomas Aquinas?

An Italian philosopher and priest of the Roman Catholic church (1225-1274)

What did Aquinas believe?

The God of Classical Theism was the God that created the universe

What idea does Aquinas reject?

Infinite regress

Infinite regress

The idea that everything is made of something before it

Example: infinite regress

A wall is made from > brick, which is made from > cement > mud > dirt > minerals > elements particles > atoms > subatomic particles > and so on…

What were Aquinas’ three main ways?

• First way - argument from motion

• Second way - argument from causation

• Third way - argument from contingency

First way - argument from motion

The idea that everything which is in the universe that is in motion has been put into motion by something else, which Aquinas says is God

What does Aquinas mean by ‘motion’?

Aquinas does not necessarily suggest ‘movement’, but any form of ‘changing matter’

How does Aquinas describe God for the argument from motion?

He was the first mover and is unmoved himself

What does Aquinas say about the ‘chain of motion’?

It cannot go on infinitely as there must have been a beginning point to the universe

What evidence is the argument from motion based on?

Empirical evidence, as it is used to notice how one thing causes motion in something else

Empirical evidence

Things people have experienced with their senses (mainly sight)

Example: empirical evidence

A pool cue moving the ball

Quote: argument from motion

“It is necessary to arrive at a first mover, moved by no other, and this everyone understands to be God.” - Thomas Aquinas

What does Aquinas add about things that are in motion?

Things can move from what they are, to what they have the potential to be

Example: something that can move from what it is to what it has the potential to be

Wood has the potential to go on fire, but the wood cannot do this itself, thus something else is required to do so, which Aquinas says is God

Second way - argument from causation

The idea that everything in the universe has a cause as the universe was created by a succession of cause

Succession

The order of things

Example: succession

When a glacier melts and retreats, it will give way to a new valley that was never there before, providing new grass for animals and new soils for agriculture

What does Aquinas say about the cause for the universe?

As everything exists for a cause, this means that the universe therefore must exist for a cause, meaning it had a beginning

Quote: argument from causation

“There is no case known… in which a thing is found to be the efficient cause of itself.” - Thomas Aquinas

Who does Aquinas say caused the universe and why?

Nothing can cause itself, not even the universe, thus an outside cause must of created the universe, which Aquinas says is God

Example: something that could not have caused itself

You could not have caused your own existence

Efficient cause

A being that is capable of bringing about an action/change by itself

Example: efficient cause

God

Third way - argument from contingency

The idea that all beings are split into two types: contingent beings and necessary beings

Contingent beings

Beings that rely on other beings for existing

Example: a contingent being

Humans (and other living beings), as you could not have existed without your parents

Necessary beings

Beings that do not rely on other beings for existing as they have always existed and will always exist

Example: a necessary being

God

Who was the first necessary being?

God, as he created the first contingent beings

Example: the first contingent beings

Adam and Eve in Christianity

What evidence is the argument from contingency based on?

The idea that since everything in the universe is a contingent being, a necessary being must have then existed to of began this cycle

What does Aquinas say about things that come into existence later on?

Everything that comes into existence later on has the potential to not exist, as it has not been put into existence yet, meaning that these things are contingent as they rely on something else to exist, which Aquinas says is God

How does Aquinas respond to the idea that at one point nothing was in existence?

He disagrees, as if this was the case then from that point onward nothing would have existed, which is false as we knowingly exist, meaning that something must have always been in existence, which Aquinas says is God

Why does Aquinas say that something must have always been in existence?

Since contingent beings come in and out of existence, a necessary being must have always been in existence as there must have been a permanent being to introduce contingent beings

Quote: argument from contingency

“Therefore if everything can not be, then at one time there was nothing in existence… If at one time there was nothing in existence, it would have been impossible for anything to have begun to exist, and even now nothing would be in existence.” - Thomas Aquinas

What two things does Aquinas say the cause of the contingent universe must be?

Outside of the universe itself and the eternal making of a necessary being (God)