Describe Aquinas' cosmological argument for the existence of God, and explain how three of the arguments fundamental premises might be challenged
The cosmological argument centers on change and also motion. This argument starts with the existence of the universe and posses the question on the very existence of the universe. The concept of Aquinas cosmological argument is on the need to explain the existence of the universe. In this assumption, the explanation is based on the activity of God. Aquinas explained the cosmological arguments in five ways: the first three concern arguments on the existence of God, the fourth way is a moral argument and the fifth way is a teleological argument. Aquinas argues that the cause of everything is what people refer to as God.
The first way in Aquinas cosmological arguments is that something causing change exists: this is based on the assumption that for change to happen there has to be a reason for it. Aquinas further explains that there cannot be an infinite number of things changing without a cause; this argument relies on the presumption of motion. Theists argue that the fact that there is an infinite series of changes, to state that the series of changes began at one point is incorrect. The second way states that in order for there to be a cause there must be a first cause, in which the first cause came about because of itself. This way is based upon the presumption of change, the first mover or changer. Some theists argue this by stating that even though every human has a mother it does not necessarily mean that the entire human race has a mother.
The third way of Aquinas cosmological argument is that for contingent things to exist there was necessity. In this argument, Aquinas tries to explain that if there were no necessity to the cause, then nothing would have existed. Aquinas tries to put forward the school of thought that everything is possible. This way is mainly based possibility and necessity, that something that is already in existence may not have been or what was not in existence may have been. Theists have argued this by questioning the reason basis of making God the orchestrator of the cause as there is no sufficient reason to justify this argument, as they do not fulfill the attribute that people say God posses. For example, it does not give a reason as to why God is omniscient; although it suggests that the first cause is powerful, it does not necessarily justify how God is omnipotent.
Although theists agree on the presumption on change and motion, they state this does not necessarily prove the existence of God, and they justify this by stating the existence of many planets, hence a different God is responsible for each planet. Many theists believe that Aquinas arguments are based upon outdated sources and are simply erroneous.