Cosmological arguments for the existence of God argue that the existence of the universe, or some aspect of it, requires an explanation, and that whatever it is that provides this explanation is what we mean by “God”.
There are different varieties of cosmological argument, but central forms argue that God is the cause of the beginning of the universe, or that God is the cause of the continuing existence of the universe. Here I focus on key points from the chapter on cosmological arguments in my book What is this thing called philosophy of religion? and my article “How to prove the existence of God: an argument for conjoined panentheism” (International Journal for Philosophy of Religion, link.springer.com/article/10.1007/s11153-018-9690-1).
The kalām cosmological argument argues that God is the cause of the beginning of the universe. Kalām refers to the ninth-century school of Arabic philosophy which developed the argument, which is particularly associated with al-Kindi (c800-c870) and al-Ghazali (1058-1111). The argument has been given a more contemporary form by William Lane Craig.
Al-Ghazali argues that physical objects are either in motion or at rest, and that both motion and rest are caused because everything which is in motion could come to rest, and everything which it at rest is capable of motion. If everything had a cause, there would be an infinite chain of causes going back into an infinite past; in other words, the causal chain of events would be an actual infinite, a set of things whose number cannot increase, of which any part is equal to the whole. But, if this were the case, the present link in the chain would never have been reached. Since the present link in the chain has been reached, the universe must have been created.
Craig’s argument, at least in outline, is simpler. He argues that everything which begins to exist is caused, that the universe began to exist, and that, therefore, the universe was caused. The first of these points – that everything which begins to exist is caused – he regards as uncontroversial, but he offers four arguments for the claim that the universe began to exist – two philosophical, and two scientific.
The first philosophical argument is designed show that there cannot be a beginningless series of events in time because there cannot be an actually infinite number of things. The argument appeals to the puzzle of Hilbert’s Hotel, a hotel which has an infinite number of rooms, all of which are full. In the first scenario, every guest is moved to the room with the next highest number in order to vacate room 1 for a new guest, and yet the number of guests is the same – i.e. infinite – both before and after the move. In the second scenario, every guest is moved to the room numbered with the double of their current room number in order to vacate the rooms with odd numbers for an infinite number of new guests, and yet the number of guests is the same – i.e. infinite – both before and after the move. In the third scenario, if the guest in room 1 or all the guests in odd-numbered rooms leave, the number of guests remains the same – i.e. infinite – both before and after they leave.
The second philosophical argument aims to show that the series of causal events in time cannot be an actual infinite because it is impossible to add to an actual infinite. A number to which we can add can only be a potential infinite, a finite number which can increase towards infinity but is not actually infinite, no part of which can be equal to the whole. Throughout its history, events have been added to the series of causal events in time, which means that it cannot be an actual infinite.
Craig’s first scientific argument is based on the Big Bang theory of the origin of the universe. He argues that, although there are other scientific theories of the origin of the universe, the Big Bang theory is generally thought to offer the best explanation, and that this supports the belief that the universe came to exist from nothing a finite period of time ago.
His second scientific argument is based on the Second Law of Thermodynamics, according to which the processes of a closed system (one which has nothing outside it) move towards a state of equilibrium in which its properties remain unchanged. Craig argues that, since the universe is a closed system, its processes are gradually running down to a state of equilibrium, and it will eventually die. If the universe had always existed, we would already have reached this point.
Thomas Aquinas (1224/5-1274) believed that God caused the existence of universe, but did not think it possible to provide a philosophical proof of this. He did, however, think it possible to prove that God is responsible for the continuing existence of the universe and the first three of his Five Ways are forms of the cosmological argument.
In the First Way, the Argument from Motion, Aquinas argues that, although nothing changes itself, there cannot be an endless series of change-causing things. There must therefore be a first mover which is not changed by anything else, and this is what is called “God”.
In the Second Way, the First Cause Argument, Aquinas argues that the existence of everything is caused by something which requires no explanation for its existence, and this is what is called “God”.
In the Third Way, the Argument from Contingency, Aquinas argues that, if there had been only contingent things – things which might or might not exist – all of which, at some point, would not have existed, there would have been a time when nothing existed. And if there was a time when nothing existed, then nothing would exist now. As things do exist now, there must be some things which exist necessarily – which must exist – and the existence of these things is caused by God.
Some objections to cosmological arguments apply only to particular versions of the argument, while others apply to cosmological arguments more generally.
One possible objection to the Al-Ghazali/Craig argument that the sequence of events in time cannot be an actual infinite because the concept of an actual infinite is irrational might be that events in time are not additions to the succession of events but points on an infinite spectrum of events. The Big Bang theory and the Second Law of Thermodynamics do, however, cast doubt on this suggestion.
An objection to Aquinas’s Third Way is that even if, at some point, every contingent thing did not exist, there is no reason to suppose that there was a time when nothing existed; there could have been an overlapping sequence of contingent things. One possible response is to say that the existence of God is required to explain the existence of the overlapping sequence. Another is to say that perhaps Aquinas was right after all because, if there were no necessary beings to cause the existence of contingent beings, there would have been a time when there was nothing at all, which means that nothing would exist now.
There are two related objections which apply to all forms of the cosmological argument. The first is: Why must we assume that the existence of the universe needs an explanation? This objection was most famously made by Bertrand Russell in a radio debate with Frederick Copleston in which he argued that the universe is a “brute fact” which is “just there”. Herbert McCabe argues that it is just as arbitrary to say that the universe is just there as it would be to claim that dogs are just there; even if we cannot answer the question concerning the ultimate origin of the universe, it is not irrational to ask it.
The second related objection is that, if the existence of God does explain the existence of the universe, why doesn’t the existence of God need an explanation? Typical answers revolve around the claim that God is a special case. For example, Craig argues that only things which come into existence are caused. Since God has no beginning, God’s existence needs no explanation; in other words, it is God’s existence which is the brute fact.
Not all religions hold that the universe was created by God out of nothing. For example, Sushanta Sen argues on the basis of teaching found in the Chāndogya Upanisad that it is only possible to produce an effect if it already exists in its cause. Just as it is only possible to produce oil from crushed seeds if the oil already exists in the seeds, so God created the universe from God’s nature. God is therefore simultaneously the creator and the physical substance of the universe.
Sen also suggests that both God and the universe exist eternally, and recommends a form of Oscillating Universe theory according to which parts of the universe are periodically reabsorbed into God and propelled out again, neither of which appear to be compatible with the current scientific consensus regarding the probable origin of the universe. But it might be possible to argue that some form of pantheism, which identifies God and the universe, or some form of panentheism, according to which the universe is “in” God, but God is more than the universe, is compatible with the current scientific consensus regarding the probable origin of the universe, and that some form of the cosmological argument can show that beliefs of this kind are rational.
In “How to prove the existence of God: an argument for conjoined panentheism”, I argue that divinity may best be understood as a conjoinment of “God the World”, and “God the Good”. God the World describes the idea that everything which exists or could exist is “in” God, while acknowledging that, since the world contains a great deal of evil, not everything which is “in” God is “of” God. For this reason, we also need God the Good, the idea that God is the universal concept of Goodness, like Plato’s idea of the Good, particularly as this is found in the work of Iris Murdoch. God the World and God the Good are conjoined because it is the nature of the world which determines the nature of goodness.
My argument to support this is developed from a form of cosmological argument found in the work of Eric Steinhart, and a form of ontological argument from my own chapter “Patching Plantinga’s ontological argument by making the Murdoch move” (in Two dozen (or so) arguments for God: The Plantinga project, edited by Jerry L. Walls and Trent Dougherty).
The cosmological part of the argument – for God the World – runs as follows. Since every complex thing is contingent, and the set of all actual and possible universes is a complex thing, the set of all actual and possible universes is a complex contingent thing. Since every complex contingent thing is derived from something of lesser complexity, the set of all actual and possible universes is the product of multiple chains of decreasingly complex things, all of which originate in one non-complex, non-contingent cause of all actual and possible physicality.
The ontological part of the argument – for God the Good – follows on from this. An ontological argument is one which argues from a concept to the existence of divinity. This version argues that the nature of actual and possible physicality determines the nature of goodness. If there are degrees of goodness, there must be an Unsurpassable Goodness. Since the set of actual and possible worlds contains degrees of goodness, Unsurpassable Goodness must exist.
God the World, then, is whatever it is which brought about the existence of the world and enables its continuing existence – both its creator and its sustainer – while God the Good is the Unsurpassable Goodness which promotes and inspires the flourishing of sentient creatures.
A key difficulty for many forms of panentheism, including the one described here, is that of explaining the sense in which the world is “in” God. G. R. Peterson argues that three metaphors which are often used to explain this relationship lack precision and need to be replaced, but, in my view, although they are not perfect, these metaphors can help us to explain how the world is “in” God. According to the locative metaphor, God and the world are differently located – the world is located within divinity, but divinity encompasses more than the world. The mind-body metaphor suggests that the world is the physical component of divinity which has at least some features which, like some processes of the human body, are not directly controlled by a conscious mind. Thirdly, the substance metaphor suggests, like the Chalcedonian Definition of the early Christian church, that God is two natures – in this case, God the World and God the Good – in one substance.
A second difficulty for many forms of panentheism is the apparent implication that, because the world contains evil, God is to some extent evil and therefore not something which we should value. But if evil is “in” but not “of” God, evil is like parasites which, in order to restore its health, must be expelled from a body, and it is God the Good which promotes and supports humankind to work for positive change.
I have argued, then, that a form of cosmological argument can be used to support belief in divinity – although the argument must be conjoined with a form of ontological argument if that divinity is to be any more god-like than a first cause of everything which exists, about which nothing more can be said. The conjoined argument therefore proves the existence of a divinity which has two conjoined natures, both physical presence and absolute goodness, neither of which could exist without the other. The ancient Greek philosopher Anaxagoras (c510 – c428 BCE) was exiled for claiming that the moon was not a god but merely a rock and, for many centuries, this has been the dominant view. But if the universe and its goodness together constitute the divine, and if divinity is construed as impersonal, or personal in a metaphorical sense, then perhaps Anaxagoras was, after all, at least partly mistaken.