Cosmological Arguments

Descartes’ argument from continuing existence

P1. I do not have all perfections, so I cannot be the cause of my own existence. 

P2. My existence at one moment does not guarantee my existence at the next, so my continued existence requires a cause. 

C1. Therefore, I depend on something else to exist. 

P3. The cause of my existence must have at least as much reality as its effect and must be a thinking thing capable of causing the idea of God. 

P4. There cannot be an infinite regress of causes. 

C2. Therefore, there must be a self-causing being that sustains my existence. 

P5. A self-causing, sustaining being is God. 

C3. Therefore, God exists. 

Scientific explanation

Explains an object or other event in terms of the scientific laws of nature.

Personal explanation

Explains an object or other event in terms of a person and their purposes.

Aquinas’ 1st Way

P1. Some things are in motion (undergo change from potentiality to actuality). 

P2. Nothing can move or change itself. 

P3. Everything in motion is moved by something else. 

P4. An infinite regress of movers is impossible, because without a first mover there would be no motion at all. 

C. Therefore, there must be a First Unmoved Mover which is God. 

Aquinas’ 2nd Way

P1. Every event has a cause. 

P2. Nothing can be the cause of itself. 

P3. An infinite regress of causes is impossible, because without a first cause there would be no causes or effects. 

C. Therefore, a First Uncaused Cause must exist which is God. 

Efficient cause

The cause that brings something else into existence or makes an event occur.

Aquinas’ 3rd Way

P1. Things in the universe exist contingently.

P2. If something is contingent, then there is a time when it does not exist.

P3. If everything were contingent, then at some time there would have been nothing.

P4. If at some time there was nothing, nothing would exist now.

P5. But things do exist now (reductio ad absurdum).

C1. Therefore, not everything is contingent; at least one thing is necessary.

C2. A necessary being that depends on nothing else must exist which is God.

Al Ghazali’s Kalam argument

P1. Everything that began to exist has a cause.

P2. The universe began to exist.

C1. Therefore the universe has a cause.

William Lane Craig’s Kalam argument

P1: Everything with a beginning must have a cause.

P2: The universe has a beginning.

C1: Therefore the universe must have a cause.

C2: Moreover, this cause of the universe must be a personal cause, as scientific explanations cannot provide a causal, or mechanical, account of a first cause. This personal cause is God.

Leibniz's argument from sufficient reason

P1. Any contingent fact about the world must have an explanation.

P2. It is a contingent fact that there are contingent things.

P3. The fact that there are contingent things must have an explanation.

P4. The fact that there are contingent things can't be explained by any contingent things.

P5. The fact that there are contingent things must be explained by something whose existence is not contingent.

C1. There is a necessary being.

Principle of Sufficient Reason

Any contingent fact about the world must have an explanation.

Leibniz’s truths of reasoning

Necessary or analytic truths.

Leibniz’s truths of fact

Contingent or synthetic truths. 

The sufficient reason for truths of reasoning

It is revealed by analysis. When you analyse and understand "3 + 3 = 6" you do not need further explanation for why it is true. 

An infinite regress of causes

A chain of causes that goes back forever, with no first cause.

The causal principle

Everything that exists must have a cause.

Hume’s objection to the causal principle

It is not analytically true so denying it is not logically contradictory. Experience cannot prove it as experience only shows what usually happens, not what must happen. Some things may exist without a cause.

Fallacy of composition

Assuming that what is true of the parts must be true of the whole.

Russel’s use of the fallacy of compostion

Even if everything in the universe is contingent, the universe itself doesn’t have to be.

The impossibility of a necessary being

Whatever we can conceive as existing, we can also conceive as not existing so no being exists in a way that it is impossible for it to not exist.