Abstract

This volume of twenty-two original papers commemorates the twentieth anniversary of Arthur Prior’s death. Eight of the papers are based on presentations at a conference held in New Zealand to the same end. The contents testify to the range of Prior’s interests and influence. After an informative biographical sketch by Copeland, which emphasizes Prior’s early discovery of accessibility-relation semantics and its ability to prove the soundness of modal systems of various strengths, there follows a group of papers on temporal logic by Prior, Copeland, Gabbay and Hodkinson, Rodriguez and Anger, and Sylvan; a group on modal logic by Meredith and Prior, van Benthem, Fine and Schurz, and Humberstone; a group on agency by Belnap, Oddie, and Segerberg; a group on proof theory by Bull, Bunder, and Tennant; a group on individuation and quantification by Harré, Lambert, Loptson, Richard, and R. Teichman; and two on the a priori, by