The Logic of Events (Annals of Mathematics and Artificial Intelligence 28 315-389. 2000.)

An event space is a set of instantaneous events that vary both in time and specificity. The concept of an event space provides a foundation for a logical--i.e., modular and open--approach to causal reasoning. In this article, we propose intuitively transparent axioms for event spaces. These axioms are constructive in the intuitionistic sense, and hence they can be used directly for causal reasoning in any computational logical framework that accommodates type theory. We also put the axioms in classical form and show that in this form they are adequate for a representation in terms of event trees.

Causality and Responsibility (Cardozo Law Review 22 101-123. 2001)

This article applies the predictive understanding of causality advocated in my 1996 book The Art of Causal Conjecture and in my 2001 book with Volodya Vovk, Probability and Finance: It's Only a Game, to the issue of probabilistic responsibility. I argue that the problem of assessing responsibility for actions that create only a probability of damage for any particular individual is best addressed by combining the classical concept of necessary and sufficient cause with a philosophy of probability that locates the empirical meaning of probability in the impossibility of successful gambling strategies. This supports the view that toxic torts should be class actions rather than individual actions.

Nature's Possibilities and Expectations (Pp. 147-166 of Probability Theory : Philosophy, Recent History and Relations to Science, edited by Vincent F. Hendriks, Stig Andur Pedersen, and Kaus Frovin Jørgensen. Kluwer (Synthese Library, Vol. 297). 2001)

A flexible and commonsensical theory of causality can be based on the idea of Nature's evolving predictions. Nature witnesses the unfolding of events at levels of detail finer than that of any actual witness, and she makes predictions of future events that are never falsified. Although we seldom see events as Nature sees them, we often conjecture about Nature's predictions from regularities we do see, and we sometimes build these conjectures into our own reasoning and prediction. Mathematically, these conjectures concern possibilities and expectations in Nature's event tree.

The Notion of Event in Probability and Causality: Situating Myself Relative to Bruno de Finetti (unpublished paper presented in Bologna and Pisa in March 2001)

As Bruno de Finetti taught us, the notion of event in a theory of probability is fundamental, perhaps determinative. In this paper, I compare the notion of event in de Finetti's subjective theory of probability with the more situated notion of event that underlies the theory of probability and causality that I have developed over the past ten years.

On the Puzzle Presented by Richard Gill (unpublished memorandum written following a workshop on causality at Santa Fe in 1997).

The memorandum explains how easily the probability-tree understanding of causality handles the paradoxes concerning quantum-mechanical correlations at a distance. For related discussion in the more general context of event trees, see Section II.7 of The Logic of Events.