Thomas Paine’s The Age of Reason is both a defense of Deism and a rejection of the world’s major monotheistic religions. Published in three parts (1794, 1795, 1807), Age of Reason reflects Paine’s belief that a significant religious upheaval would follow in the wake of the American and French Revolutions. In France, privileged orders such as monarchy and aristocracy had been toppled, and the established Catholic Church had not survived the onslaught. Paine feared that as the French Revolution descended into revenge-induced violence, the disillusioned masses would succumb to nihilism and lose their humanity. In fact, Paine completed Part 1 in a hurried fashion only hours before being arrested by French authorities and sent to prison for nearly a year.

Age of Reason offers a spiritual counterpart to the era’s political awakening. Paine believes that only Deism is consistent with the truth-seeking spirit of the age. He reserves his most scathing criticisms for Judaism and Christianity, analyzing both the Old and New Testaments and debunking what he considers their most obvious absurdities, including their claim to be the word of God. Paine regards the one true God as knowable only through His Creation and not through ancient texts that purport to reveal His word.

Most published collections of Paine’s writings do not include all three parts of Age of Reason. This guide, however, uses the Michigan Legal Publishing’s 2014 edition, which does feature all three parts.

Summary

Age of Reason’s division into three parts—published on three separate occasions—distinguishes it from most books. In some respects, it is actually three short books connected by the same broader purpose, which is to promote what Paine regards as The True Theology of Deism.

In Part 1, Paine makes his most direct appeal on behalf of Deistic theology. He did not have copies of the Old and New Testaments in front of him when he hastened to complete Part 1, so he was forced to defer extended analysis of these texts to Parts 2 and 3 and focus instead on making the positive argument for Deism. Deism is the religion of natural philosophy, which is an 18th-century phrase for science. Astronomy, according to Paine, ranks first among the sciences, for it constitutes the source of knowledge about God’s natural laws.

Paine divides Part 1 into 17 chapters and fills several of these chapters with observations based on astronomy, including the movements of the planets and their distances from the sun. This may appear as Paine venturing beyond the religious realm, but to Paine and the Deists, the study of the natural world was the only pathway to God. Paine denounces all religions based on purported revelations. Since he is writing Age of Reason in the context of the American and French Revolutions, he raises particular objections to Christianity, though he reserves his most scathing criticisms for Parts 2 and 3.

Paine’s purpose in Part 2 is twofold. First, he sets out to expose The Bible and the New Testament as Frauds and Impositions on the world. Second, he hopes to demonstrate that the veracity of one’s religious claims must depend on The Nature of Evidence: Reason Versus Revelation. Paine analyzes the Old Testament book-by-book and in Chapter 2 examines the New Testament, focusing on the four books that comprise the Gospels. Using textual analysis and internal evidence only, Paine argues that these books are filled with lies. He argues that historical and chronological evidence alone cast doubt on attributed authorship and that the books refer to people, places, or events about which the purported authors could not possibly have known. Likewise, the Gospel stories of Jesus Christ contain so many inconsistencies that Paine believes the authors of those books could not have been witnesses to the events they describe.

Seven years passed between the publication of Part 2 in 1795 and Part 3 in 1802, by which time the French Revolution had ended in Napoleonic rule and Paine was living in the United States. In Part 3, Paine applies textual analysis to the four books of the Gospel, addressing them in sequence much the same way as he analyzes the Old Testament in Part 2. Since the New Testament’s story of Jesus Christ covers only a few years’ time and occurs mainly in one location, the Gospel does not invite the same degree of historical and chronological examination. Paine therefore focuses on the parts of the New Testament where its authors describe the fulfillment of an Old-Testament prophecy about Jesus Christ. Paine finds most of these prophecies in the Book of Matthew and concludes that they are all fraudulent.

Paine insists that religious authorities, motivated by power and riches, had to have imposed Christianity on the ignorant masses, for the Old and New Testaments contain so many supposed falsehoods that Paine does not think they could have been believed otherwise. Paine concludes the book by expressing hope for an afterlife—not as a consequence of Christian-themed salvation but because of God’s eternal benevolence as revealed in Creation.