Orthodoxy by G.K. Chesterton is a book from the early 1900s, which explores the reasoning behind accepting Christianity as the logical and true religion. Chesterton begins with the statement of a problem which humanity faces every day. He claims that humans by their very nature have a double need: a desire for imagination and a desire for reason. This could also be seen as the desire for the logical and the desire for the illogical. Individuals seek a balance between the two extremes, and the fulfillment of this balance is what leads to internal peace and satisfaction.

Chesterton asserts that the only faith which can fulfill this difficult double need is Christianity. The principals of the faith allow for some interpretation of truth, but also are consistently clear about the differences between good and evil, and right and wrong. The book acts as a guide which explains how Christianity is the best choice for all human beings, not because it's outside of our world and an independent truth, but because it is the answer to our base needs and desires. Only when Christianity is seen as a way of life instead of a belief can the true power of the faith be realized.