Every physicist (naturally, this equally applies to other specialities, but I re- strict myself to physicists for definitiveness) should simultaneously know, apart from theoretical physics, a wealth of facts from different branches of physics and be familiar with the newest notable accomplishments.

in his Nobel lecture, December 8, 2003, at Aula Magna, Stockholm University.

Vitaly L. Ginzburg - Nobel Lecture: On Superconductivity and Superfluidity