S1, E4: Simply put, the sin of sloth is the sin of the lazy. According to medieval theologians, it can doom a person to Hell. Some scientists suggest that the sin of sloth may actually be a medieval diagnosis of clinical depression. Is it a sin or a disease? The historical cures for the sin of sloth range from ancient Greek doctors who fought it with herbs, to medieval monks who prescribed prayer and fasting, to early-20th-Century doctors who battled "lack-of-pep" with grafted goat glands.