Past, Present and Future

Past, Present and Future, first published in 1967, is the magnum opus of Arthur Norman Prior (1914-1969). Prior was the founding father of tense-logic: Past, Present, and Future presents his tense-logic as a powerful and precise formalism for the systematic study of the temporal aspects of reality. The book was the summation of a decade of work on tense-logic following Prior's John Locke lectures at the University of Oxford in 1956, subsequently published in 1957 as Time and Modality. Among a wide range of topics, Past, Present and Future investigates the idea of branching time that had earlier been suggested by Saul Kripke. It includes several philosophical investigations of time, from a discussion of McTaggart's paradox, the Master Argument of Diodorus, time and existence, problems regarding determinism and future contingency. Prior's discussion of these matters invited a broad scope of ancient and medieval philosophers into the modern discussion in the philosophy of time. Prior was spearheading a revolution in analytic philosophy. Unfortunately, Prior's choice of Polish logical notation has limited its influence. This new edition employs modern notation, making it accessible to a new generation of philosophers and logicians. It includes a new preface a postscript by the editors, which can serve as an introduction to this landmark work of analytic philosophy.

Arthur N. Prior

Arthur Norman Prior (1914-1969) was a New Zealand logician and philosopher who, with the development of tense-logic, began important philosophical discussions in the intersection between logic and metaphysics about time, modality, existence, and indeterminism. After presenting the John Lock lectures in 1956, Prior moved to England in 1958 where he became professor at Manchester University. When Prior published Past, Present and Future in 1967, he had returned to Oxford again, this time as a fellow at Balliol College, where he taught until he died in 1969 on a research trip to Trondheim, Norway.

Peter Øhrstrøm is Professor at the Department of Communication and Psychology, Aalborg University.
Previously, he served as Professor of Humanistic Information Science at the University of Southern Denmark, and as post-doc in History of Science at Aarhus University. He holds a PhD in the History of Ideas from Aarhus University (1980) and a DSc in History of Science from Aarhus University (1988).

Per Hasle is Professor at the Department of Communication at the University of Copenhagen and a former rector of the Royal School of Library and Information Science in Denmark. He is a former Erskine Visiting Professor at the University of Canterbury in New Zealand. Previously, he served as Deputy Head of the Department of Information and Media Studies at Aarhus University, Professor of Humanistic Information Science at the University of Southern Denmark, where he was in charge of the establishment of the university's study in Information Science, and Professor of Information Science at the Department of Communication at Aalborg University, where he also served as director of studies. He holds a PhD in Computer Science from Aarhus University (1989).

David Jakobsen is Associate Professor in Information Science at Aalborg University. He holds a PhD in the history and philosophy of tense-logic, with a focus on Arthur Norman Prior's contributions to analytic philosophy. His research centers on future contingency, tensed ontology, and the role of tense-logic in analytic philosophy. He is currently investigating the historical and philosophical significance of tense-logic for the development of philosophical theology within the analytic tradition.

Max Cresswell (1939–2024) was a PhD student of Arthur Norman Prior. His research deals with the philosophy of logic, modal logic and formal semantics. He has published on ancient Greek philosophy, logic in the nineteenth century, and the philosophy of John Locke. Together with George Edward Hughes, Cresswell was the co-author of An Introduction to Modal Logic (Methuen, 1968), the first modern textbook on modal logic.