John Craige's Mathematical Principles of Christian Theology (review)

456 JOURNAL OF THE HISTORY OF PHILOSOPHY 30:3 JULY 1992 Richard Nash.John Craige'sMathematical Principles of Christian Theolo~. The Journal of the History of Philosophy Monograph Series. Carbondale, IL: Southern Illinois University Press, 199a. Paper, $15.95. Richard Nash provides scholars of the early modern history of mathematics, theology, and philosophy the first English translation of John Craige's Theologiae Christianae Principia Mathematica and the most comprehensive study ever written of this controversial and--as Nash demonstrates--influential work of the eighteenth century. Craige's Principles contains two independent parts. In the first, Craige quantifies the decreasing probability of historical accounts. According to Craige, suspicion about the credibility of a historical account is a function of the number of witnesses, the number of times the account is reported, time, and distance from the historical event. As accounts are transmitted, time elapses, and distance increases, the credibility of the account diminishes. Craige applies his equation of decrease of probability to belief in Christianity and concludes that Christ will not return before "1454 years.., first elapse from our present time," for, according to Scripture, before the Second Coming "it is necessary first that the probability of his history should disappear" (7o). In the second part, Craige applies the same mathematical method to prove that "the value of thi~ pleasure promised by Christ is infinitely greater than the value of the pleasure of our present life. For the pleasure promised by Christ is of nondecreasing intensity and of infinite duration, but the pleasure of our present life is of finite intensity and also of finite duration" (80. From the quantities of pleasure involved in one or another pursuit, Craige demonstrates that it is wiser to pursue the Christian summum bonum than to pursue worldly pleasures. Nash's essay is a valuable introduction to Craige's Principles. His account of the intellectual background of Craige's work provides the contemporary reader with the appropriate frame of mind to read the Principles: "If... it is easy to dismiss the argument of Craige's treatise, it is due less to individual eccentricity than to the Theology being a document very much of and for a particular time" (~). In Nash's hands, Craige's work becomes a useful tool for understanding the intricacy of the views of probability in the period. Nash argues that most objections raised against Craige's Principles derive from a failure to understand Craige's notion of probability. Nash rejects the view that Craige did not know Pascal's theory of probability. Nash argues instead that Craige, following Ia~cke, rejected Pascal's theory because it is an application of mathematics that does not provide absolute certainty. The two demonstrations in the Principles are applications of the Newtonian method of deductive demonstration, which minimizes the use of induction and hypothesis. However, in his eagerness to undo the traditional view that Craige's Principles make no sense, Nash goes to the other extreme: he is often apologetic and not quite accurate in trying to legitimize Craige by reference to Pascal and Locke. Denying the view that Craige's first argument is "a travesty of Pascal's wager," Nash claims that Pascal's inductive method "provides only an approximate, probable guide," whereas the Newtonian method used by Craige in his own version of"the wager" "claims the force of certain demonstration" (39). But there is as much objective uncertainty in BOOK REVIEWS 457 Craige's "mathematical" version of the wager as there is in Pascal's version. The difference between the two versions is more one of emphasis than of substance. Pascal emphasizes the fact that despite the lack of demonstrative evidence, theistic belief (and a moral life consistent with this belief) is more prudent than disbelief. Craige and Locke agree with Pascal that the afterlife cannot be demonstrated, but set this uncertainty aside and emphasize instead the certainty--implicit in Pascal's argument--that theistic belief and a virtuous life are more prudent than disbelief and a worldly life of pleasures. So, Nash's claim that Craige's rejection of Pascal's probability theory expresses his preference for "a more rationalist view" over Pascal's "essentially fideist view" (xvii) is at best...