The cosmological argument is "a posteriori": it relies on and adapts to our experience of the world around us, with our experience of the causal chains that cause questions about how we, and the universe as a whole, came into existence. The purpose of the cosmological argument is to attempt to prove the existence of God by showing that an infinite regress of causal chains is logically impossible and, in turn, that there must have been a first cause. It highlights the problems of infinite regression and suggests the existence of God as a solution. There are different versions of the argument, the classic one being that of Saint Thomas Aquinas. Other significant figures are Leibniz and Kant. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an Original Essay The medieval philosopher St. Thomas Aquinas provided five arguments in his book, the Summa Theologica, the first three of which are cosmological: the argument from motion, the argument from causation, and the argument from necessity and contingency. In his Second Way, the argument from causality, Aquinas argues that nothing causes itself, so if the universe were to exist - which it does - there must be a first cause. It is an 'a posteriori' argument since we know from our experience that causes are ordered into causal chains.P1) There is an order of efficient causes (every event has a cause)P2) Nothing can be the cause of itselfP3) Imagine that this order of causes goes back to infinity, so there would be no First CauseP4) If (3) were true, then there would be no subsequent causes, but this is false.C) There must be a First Cause (the source of all causes) and this we call God. Aquinas argues that nothing can cause itself because if something were the cause of itself it would have to be before itself, which is impossible. Therefore, if the universe is to exist, a cause is needed before initiating a chain of cause and effect. This argument is reductio ad absurdum. Thomas Aquinas tries to argue that God must exist because denying his existence would lead to an absurd result; uses premises three and four to prove the impossibility of there being no first cause, demonstrating that if there were no first cause then the present state would not exist - something which is obviously false. In this way, Aquinas's argument about causality is based on the idea that the universe cannot be infinite. In support of premises 3 and 4 of the causality argument, Immanuel Kant also argues that an infinite chain of causes is something that, by definition, could never be completed; If the causes that bring us and the world into existence truly extended into the infinite past, then there would have to be an infinity of causes that occur before the world could come into existence. Kant argues that this is impossible, since if there were an infinite number of causes prior to the current state, then the current state could never occur. Since the current state has occurred, there cannot be infinite causes and in turn there must be a first cause, which people call God. However, the philosopher Gottfried Leibniz sees the internal regress of the universe differently, with his principle of Sufficient Reason suggests that since there appears to be nothing within the universe itself that says why it exists, one can conclude that there are sufficient reasons to believe in a great cause outside the universe. In this way, Leibniz argues that the causeless cause must exist outside the series of causes, however infinite this series may be; he maintains, in turn, that such a cause must be in them. The Third Way of Thomas Aquinas in the Summa Theologica isthe argument of necessity and contingency. This is different from arguments about motion and causality in that it is based on the contingency of the universe and everything in it.P1) Everything in the universe is contingent on something else.P2)Being contingent means that something does not need to existP3) If it is not necessary for everything to exist, at a certain time it did not existP4) If nothing once existed, nothing would exist todayP5) Things exist todayC) Therefore, there must be a non-contingent or necessary being to explain this (God )Here, Aquinas argues that since the universe is contingent, it cannot be the cause of its own existence and is not necessary. Therefore, a necessary being is required to bring the universe into existence – where all things are contingent and in turn non-necessary, God is conversely a necessary being as he is not contingent on anything else. Another simpler version of the Cosmological Argument is the Kalam Argument. This is an Islamic form of the argument which dates back to the Muslim philosopher Al-Kindi but which also saw support from the contemporary philosopher William L Craig.P1) Everything that begins to exist has a cause of its existenceP2) The universe began to existC) Therefore, the universe has a cause of its existenceIn defense of premise two, "the universe began to exist", Craig follows Kant's reasoning that a real infinite cannot exist; he states that a beginningless time series is an actual infinity and that, since an actual infinity cannot exist, a beginningless time series cannot exist. However, the Cosmological Argument also faces several objections. Perhaps the most obvious objection to Aquinas's argument about causation, known as the schoolboy's objection, is the criticism that prefaces the first - "every event has a cause" - and the conclusion - "there must be a first cause that It has no cause in itself." – seem to contradict each other. In response to this it was argued that there must be an exception to the rule and that this is demonstrated by its reductio ad absurdo form; if there were no exceptions, no causeless causes, then the universe would have no causes and could never exist. There is, however, also a reply to this response to the objection. It could be argued that instead of God being the exception to the causal rule, the universe itself could be the exception, and only things within it should follow the rule. Furthermore, we could say that the existence of the universe needs no further explanation: it simply is. A further objection comes from Hume, who, in line with his epistemology, suggests our cognitive inability to understand the nature of a metaphysical superentity powerful enough to give life to the universe. In this way, he argues that we have no reason to infer what brought the universe into existence. To assert that it is actually God requires an unwarranted inference. Hume also argues that the Cosmological Argument suffers from the fallacy of composition, an idea later supported by Russell. The fallacy of composition is the fallacy of assuming that because there is a property common to each part of a group, it follows that this property applies to the group as a whole. Therefore, although every single part of the universe may have a cause, it does not necessarily follow that the universe itself must have a cause. Please note: this is just an example. Get a custom paper from our expert writers now. Customize EssayTo conclude, the cosmological argument is an a posteriori argument whose purpose is to attempt to prove the existence of God. Both Kalam's and Aquinas's cosmological argument attempt to demonstrate this existence through means of reductio ad absurdum, demonstrating that without a, 39(4), 1-51.