Before I begin this post I would like to clarify that I believe it is of course immoral to murder but I would like to explore it purely at a philosophical level. After reading Peter Singer’s ‘Practical Ethics’, I was intrigued how humans got to this conclusion and the different arguments for this. I will mention the view of preference utilitarians, hedonistic utilitarianism and the moral principle view. I believe the moral principle view is the most commonly held view but all views are equally valid, despite a few flaws in their arguments.

Beginning with preference utilitarianism, it states that people are aware that they have a past and a future. People also have dreams and desires for the future. By taking the life of an individual it means the victims greatest dreams and desires are tarnished. Preference utilitarian's believe that utility is maximised in life when one achieves and lives by their preferences. Destroying this goes against what they believe and therefore one should not kill. In addition, people have the potential to go on and do great things in life, like become a doctor that would save millions of lives, so killing this person means killing their future, not benefiting society as a whole. Although this seems like a valid argument, one can state that murder is very emotionally focused and can be impulsive, thus people are unlikely to stop and think about the consequences of their actions, let alone how they are destroying the person's desires and dreams. This does of course depend on the background of the individual. If the murderer has a good set of values, then arguably rationality should override impulse, as this is what distinguishes us humans from impulse driven animals.

Furthermore the hedonistic view slightly disagrees with preference utilitarianism and does not take into account the status of the person, as this is not relevant to the amount of pain and pleasure one may experience in their life. Thus they take the approach that it is wrong to murder as it means the person would not be able to experience happiness in their life. On the surface, it may seem like the same counter argument for preference utilitarianism applies, but I believe this view is more rational. When an individual is murdered the happiness of others who know the person or even people who do not, is comprised. I do agree this argument has some weight as if you remove the concept of hedonistic utilitarianism , the murdering of an individual or multiple individuals can affect society not just the person killed. So it can be seen as a more plausible argument as the murder is likely to think holistically about the consequences rather than about the certain individual. It can be said that hedonistic utilitarianists may find it acceptable to kill an individual if they were going to live a future life full of pain. However, if this does occur, it should be a mutual agreement from the person and should be done as Euthanasia instead of one killing the person as murder is painful, and hedonistic utilitarians believe in pain being minimised.

Yet a counter to the utilitarian points is that one should not judge individual actions such as murder by how much utility it will provide people but instead create broad principles. It is time consuming and unrealistic to think about each individual consequences of an action and the same applies to murder, especially if it is an impulse decision. Thus society has looked at history and discovered what principles are correct and work, leading to them create standard moral principles such as do not lie and keep promises as well as do not murder. This is a view that to me seems the strongest as humans are known to be rational and moral so following the moral principle of do not kill is clearly correct. If one does not follow the principles, one will face grave consequences and possibly become shunned from society. It can be argued that in certain circumstances an individual must go against moral principles. For example if a soldier mudreded another in a battle, homicide is not against the law but if a terrorist or even a soldier who is off-duty does so, then this is not morally correct and should not occur. I do agree with this but there are very few instances when this is allowed and even then it is possible for murder to be averted. 

Overall, I think that a combination of all of the views provide evidence of why one does not kill. Mostly individuals think about themselves and make decisions based on themselves, sometimes considering others. Therefore, linking the principle theory to utilitarianism if a murderer wants to maximise their happiness and ensure they achieve their own desires they must follow the moral principle.