 Impetus for this process of development also dates from the writing of his book on philosophical nihilism, "The Specter of the Absurd", published in 1988 and from his study of, and constructive work on, theories of religion in "Interpretive Theories of Religion", published in 1981.The writing of his doctoral dissertation on Horace Bushnell’s theory of language, published in 1975 as "Horace Bushnell’s Theory of Language in the Context of Other Nineteenth Century Philosophies of Language", contributed greatly to the freeing of his mind from any vestiges of biblical or theological literalism, as did his studies of the origins and characters of the Hebrew and Christian scriptures at Princeton.In addition, Crosby’s exposure to the field of world religions at Columbia helped to broaden his thought far beyond its earlier religious conservatism.