The self-existent cosmos.

The impulse to understand causes is so strong that we apply it to everything from amoeba to our own brains, from single particles to the entire cosmos. When we see what seems to be design, we are biologically driven to ask who designed it and for what purpose.

Ironically, these drives have helped to sustain beliefs in God and gods - even though these are results of our failure to explain.

When pre-scientific peoples saw lightning flash, they assumed that gods must be hurling the thunderbolts. They designed rituals to manipulate the gods.

Today scientists try to explain the beginning and the end of the universe. Yet still no-one can explain its ultimate cause or purpose. Many people assume that God is the answer, and the arguments from cause and design remain the most commonly used "evidence" for the existence of God.

Cause.

There is no case known (nor indeed is it possible) in which a thing is found to be the efficient cause of itself, because in that case it would be prior to itself, which is impossible. Now in efficient causes it is impossible to go on to infinity. Now to take away the cause is to take away the effect. Therefore, if there be no first cause, there will be no ultimate, nor any intermediate cause. Therefore it is necessary to admit a first efficient cause, to which everyone gives the name of God. [Summa Theologica, 1.2.3]

They would not demonstrate:

What the first cause was.

Whether the first cause was material or mental.

Who or what the designer was.

What the designer's purpose was.

Whether first cause and designer were the same.

Whether first cause and designer were identical with the God of any particular religion.

Probably the most convicing purpose invented by theists is the one conceived by Mohammed, in which God created humans to contemplate him: "I was a hidden treasure, and I desired to be known." By contrast, his motives would have been - in human terms - perverse if his goal was to create humans with all their foibles and to test their ethics and devotion, only to violently wind up the whole spectacle and punish failures with eternal agony.

The arguments cannot prove that the first cause and the designer were one and the same. The first cause may have started matter in motion, which a mental designer then worked on to shape our universe. Many Gnostics believed that the material world was not created by God but by an evil Demiurge. The Roman poet Lucretius believed that the cosmos created and ordered itself, while the gods passed their lives in calm and peace.

They cannot prove that the cause and designer are the God of any particular religion, or a God of any particular character. Notice how, at the end of each proof, Aquinas leaps abruptly to the statement: "And this being we call God." But he does not prove that this being is God, nor does he prove that it is his Christian Trinitarian God as opposed to the one Allah of Mohammed or other creator Gods.

David Hume, pointed out that God's ideas were no true explanation of the material world, since a mental world required a cause just as much as any other. And if we had to stop our questioning there, then why not stop at the material world?

If I am still to remain in utter ignorance of causes, and can absolutely give an explanation of nothing, I shall never esteem it any advantage to shove off for a moment a difficulty which . . must immediately, in its full force, recur upon me… . It were better, therefore, never to look beyond the present material world.
[Dialogues Concerning Natural Religion, Part 4]
The beginning of motion in matter itself is as conceivable a priori as its communication from mind and intelligence. [Ibid, Part VIII.]

Everything, it argues, requires a cause. To avoid infinite regress, there must be a first cause.
But this first cause is something that has no cause.
Therefore not everything requires a cause.
Therefore the premise is invalid.

The quantum theory of gravity has opened up a new possibility, in which there would be no boundary to space time… There would be no singularities at which the laws of science broke down and no edge of space-time at which one would have to appeal to God or some new law to set the boundary conditions for space-time… The universe would be completely self-contained and not affected by anything outside itself. It would neither be created nor destroyed. It would just BE… What place, then, for a creator?
Stephen Hawking, A Brief History of Time, Bantam Press, 1988.

The arguments from cause and purpose stem from a confusion of language. They apply the concepts to realms where, by definition, they can have no validity.

The cause of an event must precede that event. Yet if we define the universe as including all time, then there was no preceding time in which a first cause could have taken place.

The purpose of a thing lies outside itself in time or space. Yet if we define the universe as containing all space and all time, there is no "outside" where a purpose could be lurking.

Claiming that God lies outside time, space and the universe does not advance the opposing argument. For even if we accept God into the picture, we can define a new totality, embracing God and everything that exists. That totality, again by definition, can have no cause or purpose, because there is nothing outside of it in time or space.

God is no real answer to questions of cause and purpose, for theists do not ask or answer questions about the cause and purpose of God's own existence. This does not end the chain of questions: it merely draws a curtain over the further links. The answer "God" can only satisfy us if we suspend our drive for understanding at that point. And there is no logical reason for doing so. As Hume remarked:

If we stop, and go no further, why go so far? Why not stop at the material world? [Dialogues Concerning Natural Religion, , Part IV]

A moment's reflection shows that human thought can never reach a final end to the chain of cause and purpose questions.

Is there a purpose when pebbles are blown across the sand in a desert? Is there a purpose when breakers slam into a rocky shore?

We must learn not to ask for purpose in our own existence. Of course we can have goals. We should seek to make the earth a better place for humans, and a better place for other species. But the purpose of humans as a whole, the purpose of life as a whole, or the purpose for which each individual exists in the first place, is simply to be, to play, to dance, to sing, to love, all just for the sake of it.

Sometimes materialists like Richard Dawkins or Stephen Weinberg talk about the "meaninglessness" of life in the universe. Equally, critics of materialism argue that if God did not exist, human life would be "meaningless."

But this too is an abuse of language. The universe, or the totality "universe plus God," could only possess a meaning in relation to something outside. And by definition there is nothing outside a totality. It is inconceivable that they could have a meaning.

If this is the case, then there is also no conceivable shame or loss if life and the universe have no purpose or meaning.

The universe embraces all time and all space and all things that have existed or exist now or will exist in the future.

It has no before and it has no outside.

Nothing existed before it that could have been its cause.

Nothing exists outside it that could be the source or goal of its purpose or the reference point for its meaning.

It cannot conceivably have any cause or purpose.