Although G. W. F. Leibniz’s question, Why is there (tenselessly) something rather than nothing, should still rightly be asked, there would be no reason to look for a cause of the universe’s beginning to exist, since on tenseless theories of time the universe did not begin to exist in virtue of its having a first event anymore than a meter stick begins to exist in virtue of having a first centimeter.
William Lane Craig & James Sinclair, ‘The kalam Cosmological Argument’, in William Lane Craig & J. P. Moreland (eds.), The Blackwell Companion to Natural Theology, Malden, Massachusetts, p. 184
[A] source of conviction in the existence of God, connected with the reason and not with the feelings, impresses me as having much more weight. This follows from the extreme difficulty or rather impossibility of conceiving this immense and wonderful universe, including man with his capacity of looking far backwards and far into futurity, as the result of blind chance or necessity. When thus reflecting I feel compelled to look to a First Cause having an intelligent mind in some degree analogous to that of man; and I deserve to be called a Theist.
This conclusion was strong in my mind about the time, as far as I can remember, when I wrote the Origin of Species; and it is since that time that it has very gradually with many fluctuations become weaker.
But then arises the doubt—can the mind of man, which has, as I fully believe, been developed from a mind as low as that possessed by the lowest animal, be trusted when it draws such grand conclusions? May not these be the result of the connection between cause and effect which strikes us as a necessary one, but probably depends merely on inherited experience? Nor must we overlook the probability of the constant inculcation in a belief in God on the minds of children producing so strong and perhaps an inherited effect on their brains not yet fully developed, that it would be as difficult for them to throw off their belief in God, as for a monkey to throw off its instinctive fear and hatred of a snake. I cannot pretend to throw the least light on such abstruse problems. The mystery of the beginning of all things is insoluble by us; and I for one must be content to remain an Agnostic.
Charles Darwin, The Autobiography of Charles Darwin 1809-1882: with the Original Omissions Restored, London, 1958, pp. 92-94
[W]hy is there a whole of parts rather than nothing at all? […] The reason why this whole of parts exists, rather than some other possible whole, is that this whole’s existence is logically required by the existence of its parts, and its parts exist. The parts of the merely possible whole do not exist, and therefore the actual existence of this merely possible whole is not logically required.
But why these parts? These parts exist because all of them have been caused to exist by earlier parts. Other possible parts do not exist because nothing causes them to exist.
But why is there something rather than nothing? The whole of parts is something. The reason it exists is that every one of its parts has been caused to exist by earlier parts and the whole’s existence is logically required by the existence of the parts. The reason there is not nothing is that a universe caused itself to begin to exist and the basic laws governing this universe instantiated themselves.
By thy is there such a thing as a universe that causes itself to begin to exist? The reason is that this universe’s existence is logically required by the existence of its parts and its parts exist because each of them is caused to exist by an earlier part.
Quentin Smith, ‘Kalam Cosmological Arguments for Atheism’, in Michael Martin (ed.), The Cambridge Companion to Atheism, Cambridge, 2006, pp. 192-193