As in the case of those dominoes, the first member that lies at the basis of the physical series of causation — the one who tipped the domino — cannot be physical itself, because it is not itself dependent on something other than itself. And in the same way, we reach the conclusion that creation of the physical world rests upon something without a cause outside of itself, a first cause that, in relation to nature, is supernatural and self-subsistent. Now, those of you who have taken a little philosophy of religion or otherwise thought about this will know that there are a lot of different ways of trying to circumvent this, and I have not, by any means, touched on all of them. I think one of the best atheistic representations, on the other side, is in a book by J. L. Mackie called The Miracle of Theism. However you try to deal with this argument, you will find that it indeed represents a very good demonstration of this conclusion. You may be inclined to say we’ve still gained nothing with this, because it doesn’t prove that God exists. Be patient. Take each piece out of the segments of the argument that present themselves and then move on to further reasoning. But you must understand that just this part of the argument alone is very important in the modern context, where the driving attitude of atheistic thought is always to reduce reality to the natural world. To have an argument that shows that this is impossible and there must have been some form of self-subsistent being beforehand is a great step forward and, for all practical purposes, undermines atheism in its modern form. Atheism in its modern form is always naturalistic and physicalistic, so to have shown that the world cannot be understood that way is a considerable attainment.