Another person whom I mentioned briefly, who was a post-doc at Caltech when I was a student is Carleton Gajdusek. He is a medical scientist and explorer and a man of many, many parts. Again, we were both young, we both shared this wild, how should I say, thirst for a variety of intellectual challenge. He went on in very different directions. He was a fearless explorer who could go into a quite unexplored jungle in search of adventure and medical adventures. He became very famous. He received the Nobel Prize in medicine, but always remained a man of very, very many parts, not restricted to one profession, but oscillating between many. I think that the circumstances after World War II were favourable to people like us. That doesn't mean that there were many, but there were a few. At other periods there seem to be none, but the circumstances don't allow this variety to prevail, even under the best circumstances, best conditions. But at IBM during its thirty-five years of high interest in physical and other research showed how many people, potentially, can aim in that direction. Of the many people who came to IBM there were maybe a hundred who had ill-defined goals; most of them of course have dropped out of sight, but after the research division was winding up we all realised with surprise, and for me with great pleasure, that all those who had been most successful in that place were those whose interest spanned strange combinations or fields of investigation, and those who were prepared always to drop an investigation in the middle if something more exciting was coming up and return to the first one later, again and again. This kind of flexibility, it does exist; is manifested by a few individuals at any given time; science does not need many, science probably can't accommodate many, but I very profoundly feel that science at any given time needs at least a few.