Another statistical analysis that is much more rational comes from a surprising source. The Faith and Reason Ministries, dedicated to resolving conflicts between religion and science, is led by John D. Callahan. Say each galaxy has a 50 percent chance of producing an intelligent civilization in the span of 10 billion years. Then it is reasonable that in a universe with 50 billion galaxies, there may be hundreds of civilizations existing right now, and tens of thousands of them over the life of the universe. It's just that religion's business is not rationalism.
Religion is in the business of faith and the interpretation of myth.
Yet Callahan's calculation, while simple and devoid of naturalistic factors, is far more reasonable than Dr. Asimov's or Dr. Drake's calculations, or the wistful longings of Jeffrey and Randall, which depend on specious leaps of faith.