Purposeful life needs an axis or hinge to which it is firmly fixed and yet around which it can freely revolve. As I see it, this axis or hinge has been, in my own case, strongly enough, not the love of science, not even the love of Nature but a certain abstract idealism or belief in the value of the human spirit and the virtue of human endeavour and achievement. The nearest point to which I can trace this source of idealism in my recollection of reading Edwin Arnold's great book, The Light of Asia. I remember being powerfully moved by the story of Siddhartah's great renunciation, of his search for truth and of his final enlightenment.