In the Introduction to The Problem of Pain, C.S. Lewis tells us the reasons he used to give when people would ask him why he was an atheist. The reasons are well-put, but very common: the world includes a lot of suffering which seems pointless. But then he tells us that his atheist self had "never dreamed" of raising a rather important question:
"If the universe is so bad, or even half so bad, how on earth did human beings ever come to attribute it to the activity of a wise and good Creator? Men are fools, perhaps, but hardly so foolish as that."
He goes on to outline a pretty interesting history of the development of religion, culminating in Christianity, but then returns to the question he hadn't dreamt of asking until his atheist days were behind him:
"[Christianity] creates, rather than solves, the problem of pain, for pain would be no problem unless, side by side with our daily experience of this painful world, we had received what we think a good assurance that ultimate reality is righteous and loving."
One thing that stands out to me about this Introduction, reading it this time around, is just how emphatic Lewis is that God's existence and good nature could not have been revealed by reflection on the natural world. This is rather surprising given the long tradition in Christian philosophy of reasoning from features of the natural world, to the existence of a Creator, and even a "wise and good" Creator. But this rejection of reasoning about God from nature does jive with the sorts of arguments for God he elsewhere makes.
As far as I can remember, Lewis has three sorts of arguments for God he offers in various place. The most well-known is probably the Argument from Morality. The argument goes something like this: 1. there is objective morality; 2. facts about the natural world cannot explain objective morality; 3. objective morality is something that needs to be explained (e.g., laws require a lawgiver); therefore there is a supernatural lawgiver.
Another is the Argument from Desire. It goes like this: 1. By nature we have an intense longing for something we know not what, except that we can come to know that this longing is not for any natural thing; 2. natural longings have real objects (e.g., hunger implies there is such a thing as food); therefore there is a real, supernatural something which is the object of this intense longing.
The third is the Argument from Reason, and it is, roughly speaking, this: 1. If human reason were the product of natural processes, then human beliefs would come into existence by the same sorts of causes which produce all other natural effects; 2. If human beliefs are caused in this way, then we have no reason to think they are true; 3. But we do have reason to think at least some of our beliefs are true; 4. Therefore our beliefs are not totally caused by natural processes; 5. Therefore human reason is a supernatural gift.
All three arguments focus on facts about our personal experience as thinking and feeling subjects, rather than on facts about the world out there, outside our subjective experience. And this personal approach to reasoning for God seems to fit well with Problem of Pain's Introductory focus on the violence and futility of the natural world. Don't look out there for God! Look within. What the overall significance of this might be, for Lewis's total philosophical theology, I'm not sure. But it came to mind this morning and seems worth noting.