THIS THOUGHT-PROVOKING SYMPOSIUM ORIGINATED IN A small conference organized at the London School of Economics by Government and Opposition and the papers printed here have been revised — in many cases extensively — by their authors in the light of the discussion there. With a single exception (Sir Arthur Knight) all the contributors are members of the Editorial Board or the Advisory Board of Government and Opposition, and the idea for the symposium was first put forward by one of the Editors, Professor Isabel de Madariaga.The central issue addressed in the symposium is the adequacy or otherwise of the sciences, natural and social, in providing the information required by people in various capacities — as citizens, business leaders, politicians, judges, and so on — if they are to act intelligently.