Sagan turns to the criticism that science is too narrow-minded—that its reliance on hard evidence disallows the wonder of the world or places limitations on what is allowed to be true. This traditional critique is often applied by spiritual people who believe that God cannot be quantified. However, Sagan argues, science is not placing limitations on what is physically possible—it is merely observing the laws of nature.

Science is also viewed as too reductive, describing everything in nature as the product of a few relatively simple laws. Sagan suggests that this might be consonant with a universe created by an all-knowing mind, but again points out that science is not interested in proving such a being existence—instead, its purpose is to observe and derive laws. Aspects of religion can be tested however, and this makes “religious bureaucrats and believers wary of science” (275). Sagan details which basic tenets of religions can be tested, such as transubstantiation, the belief that during communion, the Eucharist turns into the body and blood of Jesus. The efficacy of prayer can also be quantified by the history of published prayers, in particular the prayers of the public for the health of their leaders. As prayers fail and leaders die, these failures become data for study.