Doctors like to talk of the ‘art and science’ of medicine. I have always found this rather pretentious, and prefer to see what I do as a practical craft. Clipping aneurysms is a skill, and one that takes years to learn. Even when the aneurysm is exposed and ready to take a clip, after the thrill of the chase, there is still the critical question of how I place the clip across the aneurysm, and the all-important question of whether I have clipped the aneurysm’s neck completely without damaging the vital artery from which the aneurysm has grown.