In the nineteenth century, farmers, doctors, and the wider public shared a family of questions and anxieties concerning heredity. Questions over whether injuries, mutilations, and bad habits could be transmitted to offspring had existed for centuries, but found renewed urgency in the popular and practical scientific press from the 1820s onwards. Sometimes referred to as "Lamarckism" or "the inheritance of acquired characteristics," the potential for transmitting both desirable and disastrous traits to offspring was one of the most pressing scientific questions of the nineteenth century. As I argue in this paper, Carpenter's religious commitments to abolition and the temperance movement shaped his understanding of heredity. But this also committed him to a body of evidence for the inheritance of acquired characteristics that was coming under criticism for being untrustworthy. Carpenter used his popular treatises on physiology to promote these older, familiar ideas about heredity because they provided vital means of arguing for the unity of mankind and the hereditary dangers of intemperance. While early nineteenth century physiology has been seen by some historians as a challenge to religious authority, given its potentially materialist accounts of the body and the actions of the soul, this paper demonstrates how the missionary and institutional activities of the Unitarian church were ideologically supported by Carpenter's publications.