Well, you all look a little tired, and it's getting late; perhaps now is a good time to offer you some oversimplifications…….… – I've been sitting here this week listening to a large number of presentations of a very high caliber. There can be no doubt that this has been a remarkable conference. We've all learned a vast amount; I can't possibly make a coherent explanation of what I've seen and heard, any more than any one of you can. But I want to emphasise a few topics that struck me very forcibly.