OVER the years, I must have read six or eight attempts by theoretical physicists to explain to the intelligent lay reader what hadrons and leptons and quarks and now solitons are all about. Not once have I experienced that mental click of understanding that tells me I can see what they are trying to do, that I grasp what the subject looks like from the professional’s side of the fence. Molecular biologists may have been more successful in communicating the nature of their subject to non-specialists, perhaps because one can at least try to visualize those spiral strips of DNA being read off and duplicated by some tiny Xerox machine. But deep down I know I lack any real grasp of the chemistry of the thing or any feeling for the theoretical questions that must exercise the professionals.