David Heyd received his Ph.D. from Oxford University in 1976. The dissertation's topic was supererogation, which is the subject of this handbook. He then became a tenured faculty member at the department of philosophy at the Hebrew University of Jerusalem from 1976 till his formal retirement in 2014 as a full professor and Chaim Perelman Chair in Philosophy. He is still teaching part-time at the university. He has been a visiting fellow and a visiting scholar in Harvard, Berkeley, Princeton, Columbia, and at the NIH (each time for a year). In 2017, he won the EMET Prize in philosophy, which is one of the two most prestigious academic awards in Israel. His main fields of expertise are moral philosophy, political philosophy, and bioethics.