Keller is still going on about this whole morality thing. In this section he says that nature is a purely violent place, where might makes right, and that the fact that we think differently argues for a supernatural explanation.
This is just wrong. There is a gradient of intelligence in the natural world and a gradient of “moral” behavior. Many higher complexity mammals display similar behavior to ours, protecting and adopting infants, for example, even if they aren’t of their species. What about all the dogs that wait for their masters and the dolphins that save swimmers? And of course there is all the cooperation we see in nature. The violence of nature is rarely wanton, it is always to survive. We do the same thing. Keller would say it’s wrong to kill people, but it’s right to kill people to keep from being killed, or to stop a killer. That’s what animals do, kill to keep from starving, or keep from being killed.
The difference from us and animals is the extent to which we can self analyze. We use this ability to augment our instincts so we can sometimes do better than nature can by itself. We can take our instinctual notions of what is good and bad and improve them. Modify them to include more people, more species, and in more situations. I don’t think this requires any deity.
Keller says it is wrong to napalm babies, but what he really means is that he can think of no situation in which the act of napalming babies would reduce the suffering of those babies, who we value highly. If there was such a situation, say, the babies were infected with an un-treatable disease that made them invulnerable to anything but napalm, but also caused constant agonizing pain before killing them in a few weeks… wouldn’t napalming the babies be exactly the moral thing to do?
I get that that situation will never happen, which is why it seems fine to make blanket statements about morality, but there are cases of ambiguity that occur all the time and making assumptions, as Keller says we must, is not the reasonable way to find the best outcome. Maybe the expedient, which is probably why the tendency is still in the gene pool.
Here’s a challenge for you to that might help convince you. Think of an example of a moral act that a religious person can perform that a secular person cannot. Now try to think of an immoral thing that a religious person can do that a secular person cannot. I suspect that second one will be easier.