This book will be a key trailblazer in a new and upcoming field. The
author's predictive approach relies on simple and intuitive probability
formulations that will appeal to readers with a modest knowledge of
astronomy, mathematics, and statistics. Wells' carefully erected theory
stands on a sure footing and thus should serve as the basis of many
rational predictions of survival in the face of natural disasters such
as hits by asteroids or comets in the coming years.
Any formula for predicting human survival will invite controversy. Dr
Wells counters anticipated criticism with a thorough approach in which
four lines of reasoning are used to arrive at the same survival formula.
One uses empirical survival statistics for business firms and stage
shows. Another is based on uncertainty of risk rates. The third, more
abstract, invokes Laplace's principle of insufficient reason and
involves an observer's random arrival in the lifetime of the entity (the
human race) in question. The fourth uses Bayesian theory.
The author carefully explains and gives examples of the conditions under
which his principle is valid and provides evidence that can counteract
the arguments of critics who would reject it entirely. His deflection of
possible criticisms results from two major premises: selecting the
proper random variable and "reference class" to make predictions, and
the recognition that if one does not know the law that governs a
process, then the best prediction that can be made is his own formula.