Assuming S₅, the main controversial premise in modal ontological arguments is the possibility premise, such as that possibly a maximally great being exists. I shall offer a new way of arguing that the possibility premise is probably true.

The principal philosophical arguments on the existence of God are brought together here. From the ancient Greeks and Anselm to the present-day and Bertrand Russell, both sides are represented. First come the contributions of Western philosophers to the five arguments traditionally used to prove that God exists; then come the basic challenges to the them; and finally the recent writings that proble what it means to assert that God exists.

Available as a single volume or as part of the 10 volume set Supreme Court in American Society.

The notion of possible worlds — once an abstruse offspring of Leibnizian theology — seems to enjoy a new lease on life in the hands of contemporary modal logicians and semanticists. The phrase “possible world” crops up with increasing frequency, and, as it is the case with many philosophical catchwords, its very familarity creates a presumption of understanding. Yet, although some related problems, particularly the one concerning cross-world identification of individuals, have received some critical scrutiny, the very idea of possible (...) worlds has been borrowed from Leibniz, and its intelligibility taken for granted even without its theological roots.My misgivings about this notion are not due to a prejudice against the concept of the possible itself: far from “passing” away, it remains a fundamental and irreplaceable element of human thought. (shrink)

Alvin Plantinga has recently argued that there are certain propositions which are necessary but known only a posteriori. If Plantinga is correct then he has shown that the traditional view that all necessary truths are knowable a priori is false. Plantinga's examples deserve special attention because they differ in important respects from other proposed examples of necessary a posteriori truths. His examples depend on a certain conception of possible worlds and in particular on his conception of the actual world. It (...) will be argued that these examples of necessary a posteriori propositions can be understood in two different ways. According to one way of understanding Plantinga, the propositions turn out to be contingent a posteriori truths, and according to the other way they turn out to be necessary a priori truths. The plausibility of Plantinga's position is due to a confusion between the two possible interpretations. (shrink)

THE AIM OF THE VOLUME IS TO INTRODUCE STUDENTS TO THE PHILOSOPHY OF RELIGION BY ACQUAINTING THEM WITH THE WRITINGS OF SOME OF THE THINKERS WHO HAVE MADE SUBSTANTIAL CONTRIBUTIONS IN THIS AREA. THIS NEW EDITION EXPANDS THE RANGE OF TOPICS BY INCLUDING AN ENTIRELY NEW CHAPTER ON DEATH AND IMMORTALITY AND A NEW SUBSECTION ON THE MORAL ARGUMENT. THERE IS ALSO SOME NEW MATERIAL ON WITTGENSTEIN AND FIDEISM, RELIGIOUS PLURALISM, AND FAITH AND THE NEED FOR EVIDENCE. ALMOST EVERY CHAPTER (...) HAS BEEN CHANGED BY DELETIONS OR ADDITIONS TO UPDATE THE SELECTIONS AND PROVIDE MORE MATERIAL THAT IS UNDERSTANDABLE TO BEGINNING STUDENTS. (shrink)

Some atheistic philosophers have argued that God could have created a world with free moral agents and yet absent of moral evil. Using possible world semantics, Alvin Plantinga sought to defuse this logical form of the problem of evil. In this critical note, Leslie Allan examines the adequacy of Plantinga's argument that the existence of God is logically compatible with the existence of moral evil. The veracity of Plantinga's argument turns on whether his essential use of counterfactual conditionals preserves the (...) logic of this type of conditional. (shrink)

1. Causal knowledge is an indispensable element in science. Causal assertions are embedded in both the results and the procedures of scientific investigation. 2. It is therefore worthwhile to investigate the meaning of causal statements and the ways in which we can arrive at causal knowledge.

These lecture notes were composed while teaching a class at Stanford and studying the work of Brian Chellas (Modal Logic: An Introduction, Cambridge: Cambridge University Press, 1980), Robert Goldblatt (Logics of Time and Computation, Stanford: CSLI, 1987), George Hughes and Max Cresswell (An Introduction to Modal Logic, London: Methuen, 1968; A Companion to Modal Logic, London: Methuen, 1984), and E. J. Lemmon (An Introduction to Modal Logic, Oxford: Blackwell, 1977). The Chellas text influenced me the most, though the order of (...) presentation is inspired more by Goldblatt.2 My goal was to write a text for dedicated undergraduates with no previous experience in modal logic. The text had to meet the following desiderata: (1) the level of difficulty should depend on how much the student tries to prove on his or her own—it should be an easy text for those who look up all the proofs in the appendix, yet more difficult for those who try to prove everything themselves; (2) philosophers (i.e., colleagues) with a basic training in logic should be able to work through the text on their own; (3) graduate students should find it useful in preparing for a graduate course in modal logic; (4) the text should prepare people for reading advanced texts in modal logic, such as Goldblatt, Chellas, Hughes and Cresswell, and van Benthem, and in particular, it should help the student to see what motivated the choices in these texts; (5) it should link the two conceptions of logic, namely, the conception of a logic as an axiom system (in which the set of theorems is constructed from the bottom up through proof sequences) and the conception of a logic as a set containing initial ‘axioms’ and closed under ‘rules of inference’ (in which the set of theorems is constructed from the top down, by carving out the logic from the set of all formulas as the smallest set closed under the rules); finally, (6) the pace for the presentation of the completeness theorems should be moderate—the text should be intermediate between Goldblatt and Chellas in this regard (in Goldblatt, the completeness proofs come too quickly for the undergraduate, whereas in Chellas, too many unrelated.... (shrink)