The Probability of God: A Simple Calculation That Proves the Ultimate Truth [Paperback]

In North America, the subject of statistics is ruled -- with an iron hand -- by the classical approach in which hypotheses do not have probabilities based on evidence. The best that classical statistics can do with the question of hypotheses and evidence is to provide the reverse probability: How likely is it that evidence would occur given the hypothesis. Yet determining how likely an hypothesis is on evidence is exactly what people interested in proposing hypotheses - scientific or otherwise - are actually interested in: How likely is it that a causal process of some kind is going on in a population based on the evidence, for example? Getting to the answer we want goes through Bayes's theorum and applying Bayes' Theorum requires prior probabilities. Where prior probabilitites cannot be obtained statistically, as is the case when hypotheses are theoretical, they have to be obtained in some other way. The Bayesian argument is that this other way is subjective probabilities -- degrees of actual or rational subjective certainty.
This book makes this argument in a clear and accessible, yet theoretically accurate way. It is written without the unnecessary technical vocabulary the employment of which usually has the effect, intended or otherwise, of throwing sand in the eyes of non-specialist readers. This is Bayesianism for Everyman (and woman). After a philosophical chapter on subjectivism as an approach to probability, the book then explains Bayes's Theorum itself and provides some interesting, non-theoretical applications of Bayesian reasoning using simple but accurate numerical examples. Then it is on to the God hypothesis. Here again there is a philosophical chapter, this time on issues in current philosophy of religion, where an approach based on the hypothesis of Intelligent Design is rejected. The reasons given are plausible enough, but do not involve applications of Bayesian reasoning. This is something I would have liked to see, because some of the most powerful and plausible formulations of the Intelligent Design Argument are given within the Bayesian framework. It would have been nice to see this use of Bayesian Theology put up for comparision with the author's own use of it in subsequent chapters. Next comes the main course: two central chapters in which the author makes his case on the God hypothesis. Like all reviews of mystery stories, it is best to leave the ending for the reader to discover.

All in all, a fun and easy way for people to learn what they need to know about an important but neglected spproach to inductive reasoning.

Recently I wrote a review of the book 'The Probability of God' for a skeptical magazine. Looking over the reviews here on Amazon I was surprised to find that one or two people had used negative excepts from my review to sandbag the author and his work, awarding him only one star. This will not do. The Probability of God is an outstanding and thought provoking book, one with which you can disagree and still appreciate what it has to offer. I award the book four stars.

Do I regard the authors core argument for belief in a God as flawed for the reasons you have read? Yes. I do. But in the interest of restoring balance allow me to highlight the strengths of this book.

First, Dr. Unwin has presented a new and innovative way to look at belief in God. In an area where the standard arguments for theistic belief have become calcified and tedious, the author delivers a breath of fresh air through Bayesian probabilities. The mathematical framework of Bayesian probabilities also provides a badly needed field of commonality on which both sides can meet to debate the merits of the issues. The math is easy and accessible due to the effortless way the authors has with words.

Second, the provocative 67% probability figure has energized the debate and provoked a lot of interest in the issues, as evidenced not just by the flurry of reviews here on Amazon, but by the guest appearance of the author on NPR, as well as by all of the human-interest news items generated in the press. Most theistic books never manage a blip on the public radar, while the authors work is seismographic in comparison.

Third, the supporting material is worth the price of the book. The author challenges currently popular evidences for God, and his discussions on what it means to 'exist', on quantum behaviors, and the bigotry of 'Scaleism' are delightful!

In conclusion, The Probability of God is vibrant. It sparkles with wit and thought provoking arguments. Weather you are a believer in God or not, you will find something in this book the challenge you and engage your mind. If you don't agree with the author, run your own numbers. Cast your own criteria and see where the calculations lead. Dr. Unwin will show you how.

In spite of the fact that I am agnostic and have no particular belief in gods, I find myself in the unusual position of recommending that people buy this book which argues for the existence of God. That is how special this book is. I call this book is a recommended read.

Would I recommend this book? -- most certainly! In fact I have purchased additional copies for my church library and for a few "no nonsense friends." Given the nature of the subject, the book is a relatively quick read: 6-8 hours more or less, depending on a reader's interest in performing a personalized assessment in parallel with the author's.

The value of the book is not in its theology, but rather in the questions posed, and the structural and analytical tools provided to the reader. I especially appreciate that the author focuses on equipping inquisitive readers with a methodology for identifying, structuring, and assessing their own beliefs, and not on defending a particular position or belief. The pluralism allowed by the author's approach is indeed a welcome relief to dogmatic positions so often manned in matters of religion. Posturing and "Is" and "Is not" positioning are absent from this book. Readers are free to select and evaluate their own beliefs. The author's perspective encourages contemplation, not fortification.

Thankfully, the writing is witty and at tiimes delightfully humorous. The author skillfully balances the sophisitcated logic that underlies Bayesian analytical technique (more nearly the subject of the book), with light-hearted and sometimes penetrating examples. The author's discussion implies truths imbedded in probability and decision analysis methodology. 1.) Statment of the premise has a direct effect on the analytical result: i.e., careful the question, lest the indication provided by the analysis point east rather than north. 2.) In order to be meaningful Bayesian analysis must be rigorously structured and consistently applied; there-in resides the strength of a mathematical approach. 3.) Once "premise" and "structure" are established, results of alternate determinants can be calculated with minimal effort. 4.) And finally, results of iterative analyses give rise to insights as to which determinants drive results and therefore the direction of the decision.

An unexpected side benefit of the book is the interest it sparks for gaining additional understanding of the development of probabilistic thinkiing and methodology. Unwin's THE PROBABILITY OF GOD are shelved alongside Bernstein's AGAINST THE GODS, and Hacking's THE TAMING OF CHANCE: good reading all.