Immanuel Kant, a german philosopher, was widely known for his theory of the categorical imperative and respect for persons. Kant's categorical imperative stated that one should always treat others as an end, rather than as a mere means (unless you have their consent). In other words, Kant believed that we should treat people with respect, and never use them solely for one's own benefit. He believed that it was not fair to treat others as only objects with instrumental value. Why did Kant believe this? Throughout his theory, he places value on what it means to have intrinsic value. Intrinsic worth is the value that a person has within themselves. He stressed that because humans are rational beings, they have intrinsic worth and are capable of practicing autonomy, and therefore should be treated with respect. While many would agree that Kant's theory sounds logical, it brings to question what Kant believed of beings who would be classified as "not rational", such as animals. Kant is unclear where can we draw the line between what is rational and what is not, however, when applied solely to human beings, his theory makes logical sense.

Understanding Kant's theory allows us to apply it to different situations, such as punishment. Did Kant believe in punishing individuals, and if so to what extent? In order to understand his views of punishment, we must compare first the norms of punishment in America today. When one is found guilty of a crime, oftentimes they are placed in jail, or prison, depending on the severity of the crime. Americans like to believe that through this system, we can achieve rehabilitation, satisfy the victim's wishes, or even prevent future crimes. However, Kant believed this to be an unacceptable form of punishment. Punishing an individual in a form that makes them conform to your own views is wrong, because we are shaping them for their own benefit, or to fit the role that we would like them to play, and consequently, the criminal becomes a "means." In his view, we must allow the individual to practice autonomy and decide what lifestyle they would like to pursue.

While Kant believed that people should be punished, he would not be an advocate for a prison, but rather for reciprocating the same suffering. When applying Kant's views to the topic of capital punishment, one can assume that Kant would be in favor of it. He believed that criminals should be punished simply because harming someone else means they are accepting that behavior. For example, if I decide to slap someone, I am automatically deciding that I would be fine with the individual expressing the same behavior towards me. Logically, it makes sense. Treat others the way you would like to be treated because what you give is what you will get. As individuals, we naturally practice autonomy and are responsible for how we choose to treat others, so Kant would say that as rational beings we must be held accountable as well. Even when punishment produces negative results, or nothing good, punishment itself is justice. In that sense, Kant would say, yes, capital punishment is acceptable because justice means that if you kill somebody, you will get killed.