Most of the contributors to this volume are philosophers of science, but three are physicists (Leggett, Stamp, and Unruh) and one is a mathematician (Douglas). Their chapters are intended to be original contributions towards answers to, rather than comprehensive discussions of, some of the oddly exasperating and fascinating questions known collectively as the problem of the direction of time, but the chapters were written with an eye towards communicating their results to the scientifically literate non-specialist.

Most of the work in this volume was presented at the ‘Time's Arrows Today’ Conference held on the campus of the University of British Columbia in June, 1992. The exceptions are the papers by Douglas and Earman and Sklar's ‘The elusive object of desire: in pursuit of the kinetic equations and the Second Law’. I am grateful to the Social Sciences and Humanities Research Council of Canada and to the Dean of the Faculty of Arts and the President of the University of British Columbia for their generous support of that conference.

In addition I wish to express my gratitude to Philip Stamp, whose advice and assistance have been invaluable, to Roy Douglas, who has long provided for me a model of rigorous thinking, and to William Unruh, without whose help my discussion of Penrose's thought experiment in the Introduction would have been much easier to write.