It takes a long time before we really get to grips with this [Darwin's 'On the Origin of Species'] and begin to understand it, because not only does it seem incredible and thoroughly demeaning to us, but it's yet another shock to our system to discover that not only are we not the centre of the Universe and we're not made by anything, but we started out as some kind of slime and got to where we are via being a monkey. It just doesn't read well.