This volume contains the lectures of "Earlier and Recent Aspects of Super- conductivity," the 18th course of the International School of Materials Science and Technology, which was held at the Ettore Majorana Centre for Scientific Culture in Erice (Sicily), Italy, July 4-16, 1989. In the wake of the discovery of high-Tc oxides many international confer- ences have been held on the subject, mainly intended for those already working in high-Tc research. Hence, the idea evolved of organizing a school dedicated to students and young scientists entering the field of superconductivity. The...