The work at Berkeley made it clear that one couldn't assemble an atomic bomb. And it was decided then by the leaders of the project that a special laboratory should be built to assemble a nuclear weapon. The overall leader of the uranium project was General Groves, and he selected Oppenheimer as the director of the laboratory. This was a very surprising choice because Oppenheimer had been a pure theoretical physicist, much purer than either Teller or I. Not that we wanted that job, but there were many other physicists who had been much more on the practical side than Oppenheimer. But it turned out that Oppenheimer was clearly the ideal leader of a laboratory. He was qualified for that by his very quick understanding of anything. He could understand the gist of an explanation long before the other person had finished his explanation. And he could then draw the conclusions of what... what to do next, until everybody at Los Alamos was conscious that Oppenheimer understood everything much better. And we were very happy to have him as a director.