The Fourth International School on Energetics was held in July 1980 at Erice, Sicily and was devoted to the subject of Energy Demand and Efficient Use. In contrast to the Third School, we chose to concentrate on the demand side of the energy equation. The initial emphasis was on the methodology for determining demand; but it soon became clear that it is necessary to control demand also. All too often energy policy is set by the large industrial nations, or those nations blessed with a plentiful supply of fossil fuels. It seemed to us important to have the views of some repre sentatives from...