This article is a selective review of David Lewis's Counterfactuals, a challenging, provocative, absorbingly interesting attempt to analyze statements of the form “If it were the case that P, then it would be the case that Q.” I shall follow Lewis in calling these “counterfactuals,” and shall nearly follow him in abbreviating them to the form P→Q.Chapter 1, which is nearly a third of the whole, gives the analysis and proves that it endows counterfactuals with some properties which they evidently (...) do have. Chapter 2 presents some “alternative formulations” of the analysis—a logical jeu d'esprit which I shall not discuss except for the section about “cotenability.”. (shrink)

Newcomb's problem and similar cases show the need to incorporate causal distinctions into the theory of rational decision; the usual noncausal decision theory, though simpler, does not always give the right answers. I give my own version of causal decision theory, compare it with versions offered by several other authors, and suggest that the versions have more in common than meets the eye.

Newcomb's paradox was first presented by Robert Nozick and has been discussed by a considerable number of writers. You are playing a game with a Being who seems to have extraordinary predictive powers. Before you are two boxes, in one of which you can see $1,000. The other is closed and you cannot see what it contains, but you know that the Being has put a million dollars into it if he has predicted that you will take it only, but (...) nothing if he has predicted that you will take both boxes; you may take either both boxes or the closed one only. The Being has correctly predicted the choices of all who have so far played with him. What should you do?Let us call the Being the seer, and his opponent the player. I should also like to reduce the amount that may, or may not, be in the closed box to $10,000. Nearly everyone could make good use of $1,000 and better use of $10,000 or $11,000, but it is hard to say whether a million dollars would be a blessing or a curse. (shrink)

The standard use of the propositional calculus ('P.C.?) in analyzing the validity of inferences involving conditionals leads to fallacies, and the problem is to determine where P.C. may be ?safely? used. An alternative analysis of criteria of reasonableness of inferences in terms of conditions of justification rather than truth of statements is proposed. It is argued, under certain restrictions, that P. C. may be safely used, except in inferences whose conclusions are conditionals whose antecedents are incompatible with the premises in (...) the sense that if the antecedent became known, some of the previously asserted premises would have to be withdrawn. (shrink)

In their development of causal decision theory, Allan Gibbard and William Harper advocate a particular method for calculating the expected utility of an action, a method based upon the probabilities of certain counterfactuals. Gibbard and Harper then employ their method to support a two-box solution to Newcomb’s paradox. This paper argues against some of Gibbard and Harper’s key claims concerning the truth-values and probabilities of counterfactuals involved in expected utility calculations, thereby disputing their analysis of Newcomb’s Paradox. If we are (...) right, then Gibbard and Harper’s method of calculating expected utility does not adequately represent rational choice. (shrink)