• There is a great deal of emotional satisfaction in the elegant demonstration, in the elegant ordering of facts into theories, and in the still more satisfactory, still more emotionally exciting discovery that the theory is not quite right and has to be worked over again, very much as any other work of art-a painting, a sculpture has to be worked over in the interests of aesthetic perfection. So there is no scientist who is not to some extent worthy of being described as artist or poet.