Some opponents of the death penalty argue that instead of deterring crime, capital punishment actually increases murder rates because the state, through executions, devalues human life. Over 150 years ago, a Massachusetts state representative, Robert Rantoul, came to this conclusion after looking at the proportion of executions to murders in Massachusetts and several European countries. Over one hundred years later, researchers William Bowers and Glenn Pierce studied homicide records in New York State between 1907 and 1963 and found that the murder rate increased slightly in the months following an execution. To explain this phenomenon, Bowers and Pierce developed what is called brutalization theory, which reasons that state-sanctioned executions brutalize the sensibilities of society, making potential murderers less inhibited.

Many opponents of the death penalty also make the argument that because most murders are unplanned and impulsive, murderers are not deterred by capital punishment. In such an emotional state, they maintain, a murderer is unlikely to think about the distant possibility of execution. As Jesse Jackson explains, “The emotionally charged environment in which these crimes take place do not suggest a coolly calculating murderer weighing his options.”

People support or oppose capital punishment for complex, often emotional, reasons. For supporters it can be an issue of public safety or political pragmatism. For opponents it can be a sense of justice or outrage at the inequality in sentencing. Ultimately, capital punishment may be an issue of morality. Although van den Haag believes that the death penalty deters more than other punishments, he would be in favor of capital punishment “on grounds of justice alone.” He states: “To me, the life of any innocent victim who might be spared has great value; the life of a convicted murderer does not.” For van den Haag and those who share his views, retribution in the form of capital punishment is a morally justifiable and necessary response to some crimes. To others, capital punishment is always immoral. Both sides firmly believe they are right.