Aquinas' Cosmological argument
The first way- Unmoved mover- Focuses on the idea of change or motion: An object has the potential to become something different, so movement is the fulfilment of that potential. Nothing can be both potential and actual at the same time. The chain of movers cannot go on to infinity (infinite regress), since then there would be no first mover. If we trace movement back far enough, we must arrive at the first, unmoved mover. We understand this to be God.
The second way- Uncaused causer- Focuses on the idea of cause and effect: Nothing could be the efficient cause of itself. The reason for this is that it would already have had to exist in order to bring itself into existence. This would be impossible. If we trace causes back far enough, there must be a first cause. Infinite regress is impossible since there would be no first cause. Uncaused causer is what we believe to be God.
The third way- Contingency and necessity- For Aquinas, anything that had a property is referred to as a being. The world consists of contingent beings which at one time did not exist. If everything at one time did not exist, there would have been nothing in existence, since there would be nothing that could bring anything into existence. As there are contingent beings existing now, there must be a necessary being (God).
Aquinas' Cosmological argument continued
Aquinas' argument appeals to events that we see and experience in the universe (change,cause, contingent beings).
Because the argument is based on experience, it is an a posteriori argument and it is inductive.
Rejection of infinite regress- Contingent beings are temporary since at some point they come into existence and at some point will go out of existence. Contingent beings cannot regress infinitely as they are temporary by nature. The only explanation for existence of contingent beings is a necessary being. Infinite regress is to deny any final explanation. The choice is between no explanation (infinite regress) and explanation (what Aquinas called God).
Each of Aquinas' 3 arguments concludes in the existence of a being which is what he understands to be God.
God is not one more in a line of movers or causers. God is of a totally different order and not subject to the same conditions as the universe.
The arguments do not attempt to fill out or demonstrate the whole nature of God. Aquinas concluded that the unmoved mover/uncaused causer/necessary being must describe God.
The Kalam Argument
This was suggested by Islamic scholars such as al-Ghazzali, and argues that God is the originating cause of the universe.
It goes: everything that has a beginning of existence must have a cause; the universe begin to exist; the universe has a cause; the cause is God.
Modern versions come from scholars such as William Lane Craig, who points out that the Big Bang shows that the universe had a beginning
Key criticisms of the argument and possible respon
The universe is 'just there'- it provides no explanation. The possibility of the universe as a brute fact- Rejection of principle of sufficient reason. No explanation needed. - Explanation sought in every other area of enquiry. If there is explanation then it could be God.
The universe must have a cause. Because an event in the universe has a cause, it does not mean that the universe itself must therefore have a cause (fallacy of composition). - Composition is not always a fallacy (e.g. every part of a silver coin is silver, therefore the whole coin is silver.)
Identity of necessary being as God. Why should the identity of the necessary being equate to God?- Aquinas never claimed the necessary being showed the attribute of God in the Christian tradition, but it is consistent with the idea of a transcendent being.
Argument based on observation. It draws a conclusion that goes beyond the evidence: David Hume (1711-76) argued that we could not have knowledge about concepts such as cause and necessary beings as they were not open to the empirical approach.- We distinguish between cause and coincidence. Reason also leads to knowledge.
Strengths and weaknesses of the cosmological argum
Strengths- It gives an explanation.
Science supports a beginning to the universe.
Consistent with God as the explanation.
Part of the cumulative argument for God.
Weaknesses-Not a proof.
Matter could exist necessarily without God.
Criticisms are persuasive.
If God doesn't have a cause, then why should the universe also not have a cause?
The cosmological argument is not the strongest argument for the existence of God, so it does little to strengthen the cumulative argument.