On the other hand, some philosophers reject Deontology as an ethical code. Nietzche states that Kantian ethics are contradictory as Kant claims that humans do not need a god to rely on for moral law, yet he believes that the existence of a moral law is evidence for the existence of a moral law giver. In addition, Kant says that the average human lifespan may not be long enough for someone to reach sunnum bonum and therefore we must have an immortal soul. This conflicts with Nietzche’s rigid secular and sceptical views as Kant rejects his formal logic.
Furthermore, Hegel brings forward the ‘rigorist’ critique which highlights how inhumane Kant’s radical deontology is. In reality, nobody would tell an axe-murder where their mother was hiding. However, Hinman argues that the inflexibility of Kant’s ethics are in fact a strength as this means that the individual is wholly committed to performing their duty. Secondly, Hegel thinks that Kant’s focus of the principle of the Categorical Imperative and duty is too abstract. This is because duty is not objective, rather subjective to a number of interpretations. When an ethical concept is based on an ambitious concept such as duty, it is likely to go wrong. Although, Pettit says that Deontology avoids errors that consequentialist theories may have, such as human error when predicting the consequences of their actions.
Lastly, Hume’s counter-argument questions the idea of Kantian ethics that actions of genuine moral worth must rest of the motive of duty. Hume says, “no action can be virtuous or morally good, unless there be in human nature some motive to produce it, distinct from the sense of morality”. Here, Hume says that it is illogical to believe that someone acts from the motive of duty unless there is some ‘natural passion’ providing another motive to perform the action in question. This implies that Kant’s argument that we do not rely on a god for our morality cannot be true.
Frances Kamm introduces the Principle of Permissible Harm as an effort to derive a deontological constraint whilst relying on the categorical imperative. Kamm here states that one may harm another in order to save more if and only if the harm is for the greater good e.g, divert a runaway trolley that would otherwise kill 5 people and allow it to kill only one person. This principle adds flexibility to deontology and acts as a response to critiques that state that deontology is too absolutist.
In conclusion, deontology serves less of a risk than consequentialist theories as there is no need to predict anything. However, the major flaw of deontology is that it does not complement basic, human nature. By demanding that humans ignore their natural emotions and focus on their so-called duty, deontology does not work. This is because for many, their emotions override their duty or even, their duty is intact to follow their emotions as Jonathan Swift said, “it is useless to attempt to reason a man out of a thing he was never reasoned into”.