"....if it's difficult to know where God is when bad things happen, it is even more difficult for atheism to deal with the problem of evil. The reason is that in a purely materialist universe, immaterial things like good and evil and souls simply do not exist. For scientific atheists ... Cho's shooting of all those people can be understood in this way - molecules acting upon molecules."
Dinesh D'Souza writing on the Virginia Tech murders.
He's correct, of course. If all we are is a collocation of atoms then what we do is just the product of chemical reactions in the brain. Those reactions follow the laws of physics, and there's no room in this picture for something like morality and no reason to think that what we do is either good or bad. It's just molecules doing what molecules do.
RLC