Welcome to cosmology
The cosmological argument can be traced right back to the dawn of philosophy in Ancient Greece. But, the most famous version comes from every Catholic’s hero: Thomas Aquinas (see right). Aquinas wrote in the 13th century and is the guy behind most of the Roman Catholic Church’s theology – even today. Cosmology aims to prove G/d’s existence by using the world around us, our a posteriori experience. This is unlike the ontological argument, which aims to prove G/d’s existence by moving from a definition of G/d to the concept of G/d.
What is cosmology?
Well, and I know we open with this every time, but it’s all in the name. Cosmology is from the Greek word κοσμολογία, meaning world or universe. So, cosmology is all about using the world around us as a proof for G/d’s existence.
Exempli Gratia
The sun rises and sets each day. Nobody tells it to... it just does.
Why does it do this? Why is there something rather than nothing?
Quinque viae (Five ways)
Aquinas put his arguments for the existence of G/d into his five ways, or qunique viae in Latin.
| 1 | Prima via | Motus | Argument from motion |
| 2 | Secundum via | Causa | Argument from cause |
| 3 | Tertia via | Argument from contingency and necessity | |
| 4 | Axiology | Argument from perfection [not discussed here] | |
| 5 | Teleology | Argument from design [see teleology] |
Who was Thomas Aquinas?
All you need to know about Thomas Aquinas in four easy-to-remember bullet points:
- He was a Dominican friar
- He lived during the 13th century
- He was influenced by Aristotle
- He put forward the Cosmological Argument in ‘Summa Theologica’
Prima via (First way)
| P1 | Everything is in motion. |
| P2 | In order for movement, something’s potentiality (potentia) must be actualised (actus) by something already in a state of actuality. |
| P3 | Nothing can be simultaneously in a state of potentiality and actuality, so nothing can move itself. |
| P4 | Following from P3, everything must be caused to move by something else. There cannot be an infinite chain of movers. |
| C | Without a first mover, there would be no subsequent movers.
Reductio ad absurdum: We know there are subsequent movers, and
thus there must be a source of all change. Ex hoc dicemus Deus. (This is what we call G/d.) |
Secundum via (Second way)
| P1 | Everything that occurs has an efficient cause, and that cause also has a cause. |
| P2 | Nothing, then, can cause itself since a cause always exists before its effects. |
| P3 | There cannot be an infinite regress of causes because if there was no first cause there would be no subsequent causes. |
| P4 | Reductio ad absurdum: Must be causes as we have effects. |
| C | Therefore, there must exist a first cause that is itself
uncaused. Ex hoc dicemus Deus. (This is what we call G/d.) |
Infringing Aristotle’s copyright: unmoved mover
Aristotle
Aquinas updates the unmoved mover for a Christian audience.
Actus and potentia (Actuality and potentiality)
It can seem a little confusing, but it’s easy once you get the hang of it. Do you remember process diagrams from Key Stage 2 maths? There would be three boxes, marked ‘input’, ‘process’ and ‘output’ and a number in two of those boxes. It’d be your task to work out the missing number. So, an input of 2 and a process of x3 gives an output of 6. In the same way, an input of 2 and an output of 6 gives a process of x3.
Where am I going with this? Well, you can do the same with cosmology! Check this out...
Bree's potentiality is actualised through motion.
What’s the difference between the two?
It’s critical that you understand the distinction between act and potency since they’re essentially opposing states.
Exempli Gratia
If you think of me, I can possess the ability to become a teacher, but
that doesn’t mean I am a teacher. I can’t both have the ability to become
a teacher, as well as being a teacher.
Here's another example, wood:
Wood can burn, but it can’t possess the potential to burn and both be burning at the same time... it’s logically impossible. When the wood is burning, it is a realisation of the wood’s potential to burn.
Ready to move on? Let's...
Aristotle’s legacy once again: the efficient cause
Yet more evidence of Aquinas pilfering ideas from Aristotle! The efficient cause is the agent which brings something about.
Exempli Gratia
My college has commissioned a statue of me to be built at the entrance,
because I’m so great. In this case, the person chiselling away at the
marble, and the act of chiselling itself, is the efficient cause because
it causes the statue.
So, from that we can infer that the efficient cause is in a state of actuality (in actus) as it needs to be so in order to cause. For Aquinas, G/d becomes the efficient cause.
WWW: IR?
Let’s call time out for a moment and ask what’s wrong with infinite regression? According to Aquinas, we need a being that is actus purus (pure act) that is only actuality and has never been potentiality to make sense of our existence.
But, by rejecting infinite regression, Aquinas’ argument is flawed.
- His conclusions thus far state that there is a first cause/mover, but the premises state everything must have a cause. How’s that working?
- Even if we get over that quite glaring flaw, what’s to say that the first cause/mover that Aquinas talks of still exists today? My father’s granddad and grandma are dead, but my father’s parents and my father are still here.
David Hume
All about David Hume (see right) in three easy-to-digest bullet points:
- Scottish philosopher
- 18th century, during the enlightenment
- Empiricist (knowledge via senses) and deist (belief in a creator G/d, that’s no longer involved)
Hume asked a very valid question:
Must every event have a cause?
For Hume, it’s not an analytic truth... the only way we can know that every event has a cause is if we verify it using our experience. We have no experience of the beginning of the universe, so this can’t happen.
Not only that, but the beginning of the universe is hardly comparable to other causes:
Tag: Copleston
Where Aquinas leaves off, Copleston picks up... they make a good team! He clarifies Aquinas’ argument...
Aquinas isn’t speaking of a horizontal series of causes:
But instead of a vertical hierarchy of causes:
The difference being that any of the causes in the linear sequence (the horizontal causes) can be removed and can work independently of each other. In the hierarchy, each cause depends on the cause above.
Causes in fieri and in esse
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| in fieri | in esse |
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G/d is cause in esse:
The ultimate ontological being.
Contingency and necessity... huh?
Just a quick summary, for those who’ve forgotten:
- Something that is necessary relies on itself alone for existence.
- Something that is contingent requires other factors for its existence.
Exempli Gratia
I’m contingent, since I rely on oxygen to keep me alive. Take away oxygen
and I’ll die, and I’d wager that suffocation is a terrible way to die.
G/d, on the other hand, is necessary. G/d doesn’t need oxygen to survive,
G/d has his (or its rather) own reason for existence.
Copleston's argument
| P1 | Everything in the universe is contingent and might not have been. |
| P2 | The universe, then, is the totality of all contingent things and is itself contingent. |
| P3 | Following that, the necessary cause of the universe must be outside of it. |
| C | Therefore, there exists a necessary being that sustains all contingent beings. |
Copleston’s interpretation conforms with Aquinas’ third way...
Tertia via: contingency and necessity (Third way: contingency and necessity)
Prima pars (First part)
| P1 | All things existing in this world are contingent. |
| P2 | If all things are contingent, then at some point there was nothing. |
| P3 | If at one point there was nothing, then nothing exists now. Reductio ad absurdum: this is false, since things do exist now. |
| P4 | Needs to be some being which is the cause of all contingency. |
Secundum pars (Second part)
| P5 | All necessary beings have their cause of necessity either inside or outside of themselves. |
| P6 | Imagine each necessary being has its cause of necessity outside of itself. |
| P7 | If P6, were true, there would be no ultimate cause of reality. Reductio ad absurdum: following the second way (secundum via), this is false. |
| C | There must exist a de re necessary being, which causes and
sustains all other necessary and contingent beings. Ex hoc dicemus Deus. (This is what we call G/d.) |
Note the two parts to this proof
- Aquinas was writing in the 13th – 14th centuries, where people believed in the existence of Angels.
- The Nine Orders of Angels are necessary, so had he stopped after the first part, it would have been reasonable to accept that an angel could have created the universe.
De re and de dicto beings
| [no visual representation] |
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| de re | de dicto |
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The third way is like a padlock
Aquinas’ third way conveniently locks his arguments so far into place, binding them to form a proof.
- Nothing can move/cause G/d.
- Nothing can move/cause G/d’s non-existence.
- Nothing that moves/causes can be accounted for without G/d.
Final thoughts
Three down, two more to go. Here we’ve covered Aquinas’ first three ways and a few criticisms from David Hume.
We don’t cover Aquinas’ fourth way, the argument from perfection, but you’ll find plenty of information about it in your local library. The fifth way is Teleology, the argument from design, which we’ll discuss in our next instalment.
Stay tuned.
Footnotes
- Depiction of St. Thomas Aquinas from the Demidoff Altarpiece by Carlo Crivelli - Image from Wikipedia (en). Used on Pisp.co.uk as it is public domain under EU law.
- Aristotle
- Portrait of David Hume by Allan Ramsay - Image from Wikipedia (en). Used on Pisp.co.uk as it is public domain under EU law.
