Controversy over the death penalty is recent in the history of humankind. Most ancient societies accepted the idea that certain crimes deserved capital punishment. Ancient Roman and Mosaic law endorsed the notion of retaliation; they believed in the rule of “an eye for an eye.” Similarly, the ancient Egyptians, Assyrians, and Greeks all executed citizens for a variety of offenses, ranging from perjury to murder.

Adherence to the death penalty continued into the Middle Ages, during which religious crimes such as sacrilege, heresy, and atheism were punishable by death. European settlers brought the death penalty to the American colonies, where idolatry, witchcraft, blasphemy, murder, sodomy, adultery, rape, perjury, and rebellion were all capital crimes in 1636. This continuing use of the death penalty reflected society’s belief that severe crimes warranted severe punishments and that such punishments...