Heretics is a collection of 20 essays originally published by G. K. Chesterton in 1905. While the loci of the chapters of Heretics are personalities, the topics he debates are as universal to the "vague moderns" of the 21st century as they were to those of the 20th. He quotes at length and argues against atheist apologist and eugenicist Joseph Martin McCabe extensively, delivers diatribes about his close personal friend and intellectual rival, George Bernard Shaw, as well as Nietzsche, H. G. Wells, Rudyard Kipling and an array of other major intellectuals of his day, many of whom he knew personally. The topics he touches upon range from Cosmology to Anthropology to Soteriology and he argues against French nihilism, German Humanism, English Utilitarianism, the Syncretism of "the vague modern", Social Darwinism, Eugenics and the arrogance and misanthropy of the European Intelligentsia. Together with Orthodoxy, this book is regarded as the finest flagship of his corpus of moral theology; a binary system in the cosmos of western philosophy.

This edition includes an author biography and discussion of his writings.