In Tower of Babel, philosopher Robert Pennock compares the views of the new creationists with those of the old and reveals the insubstantiality of their arguments. One of Pennock's major innovations is to turn from biological evolution to the less-charged subject of linguistic evolution, which has strong theoretical parallels with biological evolution both in content and in the sort of evidence scientists use to draw conclusions about origins. Several chapters deal with the work of Phillip Johnson, a highly influential leader of the new creationists. Pennock explains how science uses naturalism and discusses the relationship between factual and moral issues in the creationism-evolution controversy. The book also includes a discussion of Darwin's own shift from creationist to evolutionist and an extended argument for keeping private religious beliefs separate from public scientific knowledge.