David Hume criticized all the classical arguments for God’s existence through his book “Dialogues Concerning Natural Religion“, which was published after his death in 1776.  The Dialogues take place between four characters, with the interaction between Demea, a deist, Cleanthes, a theist and Philo, a sceptic, being the focus.  Most scholars see Philo as a vehicle for Hume’s own views and arguments and because of this, A Level textbooks list simplified versions of Philo’s criticisms of the classical Cosmological and Teleological arguments from the Dialogues and credit them to Hume.  It is probably fair to say that if the textbook was the sum total of one’s reading it would be easy to conclude that Hume was unsuccessful in arguing that observation does not prove the existence of God, in every case other than the criticism that the arguments do not support belief in all the attributes of the Christian God, which Christians accept in any case.  Few believers suggest that arguments for God’s existence are sufficient support for Christian faith in themselves. For example, when the textbook suggests that Hume asks “and what caused God” in response to Aquinas’ Cosmological Argument, it would be natural to criticize Hume for missing the more subtle point that Aquinas is making about God’s necessary existence.  Nevertheless, if one reads “Dialogues Concerning Natural Religion” it becomes clear that the criticisms Hume places in the mouth of Philo are subtle and support the conclusion that Hume was indeed successful in arguing that observation does not prove the existence of God.

In Part VIII of the Dialogues, against a very basic form of the Cosmological Argument for a “voluntary agent or first mover” Philo points out that nobody can know whether all things in the universe have a cause, that it is fallacious to make the leap from all things in the universe being caused to proposing that the universe itself has a cause.  He points out that for all we know some things in the universe could exist or happen without a cause… why not some natural process rather than a supernatural, divine agent deciding to create.  He argues in favour of the Epicurean Hypothesis, the idea that the universe could be actually infinite, which was the commonly accepted scientific world-view at the time, rooted in Aristotle.

“But this presupposes, said Demea, that matter can come to move without any voluntary agent or first mover.  And where’s the difficulty in that? replied Philo“

Superficially, Philo’s criticisms appear ill-founded.  William Lane Craig and other Christian apologists argue that an actual infinity of causes is impossible and suggest that Big Bang theory supports them in the need for an absolute beginning for the universe as a whole and so in the need for an uncaused cause.  However in fact, modern Physics supports Philo’s reasoning.  Although it is true that the standard model suggests that time and space had a beginning – the Big Bang – no Cosmologist today sees the Big Bang as the absolute beginning in the sense of needing a divine cause to explain it.  Stephen Hawking responded to a question about whether the universe needed a cause by saying that the question makes no sense to ask.  True, causation applies within time and space, but within the singularity there is no sense in which it could apply.  Cause and effect imply time and space; without either it makes no sense to think in terms of causation.  Further, research confirms the hypothesis that (at least at the Planck scale) things in the universe exist and happen without a cause and it is possible that the natural action of sub-atomic particles could account for the Big Bang.  Whatever the apologists claim, it seems that modern science supports Hume’s criticism of the attempt to prove God from observation and does not support the existence of God as the necessary uncaused cause.

In addition, through parts 8 and 9 of the Dialogues Philo makes the important point that…

“I won’t even allow any one part to justify conclusions about another part”

This is a point that builds on one he made in relation to the teleological argument in Part II

“can it be proper to argue from parts to the whole? Doesn’t the great disproportion between part and whole bar all comparison and inference?”

While superficially flippant, Philo’s point is actually subtle and far-reaching and extends beyond the point that the arguments from observation depend on the Fallacy of Composition.  Although it what is true of parts is not necessarily true of the whole, it still could be so the most damage that the classic textbook criticism of the Cosmological Argument could do is to point out that the conclusion needs more support, not that the argument has no merit.  In fact, Philo’s criticism of the Cosmological Argument is more damaging than the technical point about relying on the Fallacy of Composition.  He points out that the argument makes the massive assumption that the part of the universe we can observe is a fair sample, that the whole universe behaves as this part behaves, and that the way we see the universe is the way it really is.  The Cosmological Principle was first spelt out by Isaac Newton and Astronomer William Keel states that it…

“amounts to the strongly philosophical statement that the part of the universe which we can see is a fair sample, and that the same physical laws apply throughout. In essence, this in a sense says that the universe is knowable and is playing fair with scientists” [The Road to Galaxy Formation, 2006]

Following the discovery of Quantum Physics, science has had to abandon the Newtonian paradigm to the extent that today, the “Cosmological Principle”, the very principles of homogeneity and isotropy, are being questioned – even though that leads to the unwelcome conclusion that science is extremely limited in what it can claim to know about the universe.  Philosopher Karl Popper criticized the Cosmological Principle on the grounds that it makes

“our lack of knowledge a principle of knowing something”

concluding that

“the “cosmological principles” were, I fear, dogmas that should not have been proposed”

and since then some Physicists have come to similar conclusions, including Steven Weinberg.  Scientists might be as reluctant to accept the force of Philo’s argument as believers, but that doesn’t take away from the fact that there is no way to know that the way we perceive causation is actually what is happening or that the principle of causation that appears to apply here also applies everywhere in the universe, let alone to the universe as a whole.  Certainly, what is true of parts of the universe is not necessarily true of the whole of the universe – but further, it is not possible to say what is true of parts of the universe and let alone what might be true of the whole.  This argument of Philo’s alone shows that attempting to prove God from observation is impossible.

Further, also in Part 9 of the Dialogues, Philo attacks a version of the Cosmological Argument presented by Demea that echoes Jeremiah Clarke’s a priori argument. While not strictly an argument from observation, this version of the cosmological argument deduces God’s necessary existence and attributes from the contingent nature of other existences.  Nevertheless, unless one is an idealist, understanding what it means for other things to exist must depend on observation, so it is worth considering Hume’s refutation of this version of the argument here.  Although in 1996 Joseph K Campbell successfully argued that Philo fails to defeat this version of the Cosmological Argument – leaving open the possibility that God could be the necessary sustaining-cause of the universe – Philo’s point in asking why the cause of the universe would have to be intelligible renders Campbell’s argument in support of proving God from observation only a technical victory.  While it is true that there might be the necessary sustaining-cause of the universe, it is also true (as Philo contends) that it is not meaningful to claim that this sustaining cause has the attributes of the Christian God.  Jeremiah Clarke faced the same difficulties as Aquinas in trying to marry the attributes of a necessary being with those of the object of Christian faith.  Neither thinker manages to do more than imply that Christian faith is misplaced, because there is no way that the being indicated by contingent existence could create or act in the way that the God of Abraham and Isaac creates and acts, let alone provide hope for salvation and/or personal survival beyond death.  Nobody seriously claims that the Higgs Boson is omnipotent, let alone omniscient or omnibenevolent.  Nobody worships quarks.  Even if God might be whatever sustains the universe in being, there is no way to support religion on that basis.  Further, there is now a sensible natural explanation for the universe which obviates the need to call the necessary sustaining cause of the universe “God” and so muddy the waters of Cosmology with Theological assumptions and associations.  On this point also, despite Campbell’s work, Hume’s argument against proving God from observation has been vindicated.

Philo provides numerous other criticisms of the arguments from observation.  For example, through Parts II-V of the Dialogues, Philo criticizes versions of the Teleological Argument presented by Cleanthes, pointing out that the analogies Cleanthes employs are weak, that there is no way to establish that everything in the universe which appears to have order and purpose really has, and that (because like effects prove like causes) the universe suggests a cause or designer who is far from perfect, not necessarily single and either way a long way from being the God of the Christian religion.

“what shadow of an argument, continued Philo, can you produce, from your hypothesis, to prove that God is one being? A great many men join together to build a house or ship, to found and develop a city, to create a commonwealth” … “For all he knows, the world is very faulty and imperfect by certain higher standards… only the first rough attempt of some infant god, who afterwards abandoned it, ashamed of his poor performance… the work of some dependent, inferior god, whose superiors hold it up for ridicule… produced by some god in his old age and near-senility, and ever since his death the world has continued without further guidance, activated by the first shove he gave to it and the active force that he built into it.” (Part V)

As JCA Gaskin has argued, Philo’s individual criticisms are compelling, highlighting one by one the flaws and leaps in reasoning in two distinct versions of the teleological argument.  They are far more serious than Philo’s flippant tone might suggest, as they demonstrate how far short of proving the existence of the Christian God classical arguments fall and how much believers must depend on revelations and authority. 

In addition, the broader criticism implicit in Philo’s line of argument is conclusive; despite the multi-layered theodicies of St Augustine and St Thomas Aquinas, and the less complete but more pastorally satisfying Irenaean theodicy proposed by John Hick, there has as yet been no satisfactory explanation of why a perfect creator would create an imperfect world.  As JL Mackie observed in his essay “Evil and Omnipotence” (1955), St Augustine’s Free Will Defence fails to explain why an omnipotent God could not create free beings who always choose to do what is right.  Further, St Thomas Aquinas’ approach to redefining evil as a lack of good and God’s attributes as meaning that He can do only what is actually possible and compatible with His wholly simple nature fails to do justice to the reality of peoples’ faith.  The problem of evil and suffering remains the most persuasive objection to attempts to argue to the God of Christianity from observation.

In conclusion, Hume’s arguments – as proposed through the character Philo – successfully show that attempts to prove God from observation all fail.  The Dialogues Concerning Natural Religion present a persuasive case against belief in any sort of God which goes well beyond the petty point-scoring that the genre and style of the piece suggests.  Nevertheless, while extremely persuasive, Philo’s line of argument is a skeptical one and there significant implications flow from accepting it.  Philo casts doubt not just on belief in God, but also on the human ability to know that what we observe is really what we observe and on the human ability to deduce natural laws of any kind on the basis of observation.  By this argument, people wouldn’t just have to drop their belief in God but also their belief in science, something which few people are willing to do.  This, perhaps, is the best objection to Philo’s arguments against the attempt to prove God from observation, that they surely and persuasively lead people into a pit of despair.  However, it is not reasonable to conclude from this that the arguments from observation prove God or that Hume’s criticisms, as presented through Philo, are less than successful.