So far, we have discussed two ethical approaches: utilitarianism and Kantian ethics. These are two different ways to decide if an action is good or bad. Utilitarianism is the view that what is good is what maximizes net happiness. Kant's ethical view is that what is good is what is done for the right reasons, namely that actions are motivated by the good will. Specifically, Kant thinks that an action is moral if and only if the rule being followed can be made a universal law.
In Nagel's article "Moral Luck" , he suggests that utilitarianism must be modified because the consequences of an action are often beyond the control of a person. In short, Nagel argues against a utilitarian position on the grounds that moral actions are not moral merely by luck. If an action only has good consequences because of luck, then we cannot say that the person acting is the source of the moral value of the action. A person whose action is only good because he is lucky is not deserving of moral blame or praise. Likewise, if an action has terrible consequences only due to luck, then the person acting is not blameworthy.
For example, imagine two people: lucky Lae and unlucky Usagi. Lae and Usagi both throw a banana peel out the window. Now, Lae's peel just happens to be picked up by a cleaning crew within minutes. Usagi's banana peel, however, sits on the ground until someone slips and falls on the peel. It is only a matter of luck that determines what the consequences of the action are. Lae and Usagi both perform the same action. Nagel thinks that neither Usagi nor Lae are more morally responsible than the other.
Nagel bases his argument on the control intuition, which is the notion that if the consequences of an action are not in the control of a person, then he or she is not morally responsible for those consequences. In short, you are not responsible for random lucky (or unlucky) consequences of an action. Kant's theory fits in with this view because Kant thinks that only the motive or will behind an action is relevant to whether an action is good or bad. Although Kant does not advocate for the control intuition, his theory is compatible with it, since Kant thinks that unlucky consequences of an action do not make an action bad so long as the action was done for the right reasons.
Nagel describes four different kinds of moral luck. Resultant luck is just luck about the way our actions turn out. For example, when I play the lottery, it is a matter of resultant luck whether I win or lose. Circumstantial luck is luck about what kinds of situations or circumstances are presented to us. For example, it is a result of circumstantial luck which lottery I am able to play. Constitutive luck is luck about what kind of person you are. Namely, the temperament, capacities and inclinations that you have are the result of luck. For example, the fact that I have a strong desire to play the lottery is a result of constitutive luck. Causal luck is luck about how I have been causally determined by previous events and actions. This is really a mix of circumstantial luck and constitutive luck. For example, it is a matter of luck if my unlucky desire to play the lottery and my ability to play the Powerball lottery both cause me to actually play the lottery.
Nagel thinks that resultant luck and circumstantial luck should play and do play a role in determining if an action is good or bad. Nagel thinks that constitutive luck does not and should not play a role in whether an action is moral.
Nagel's argument can be used against both utilitarianism and Kantian ethics. Utlitarianism is wrong because it allows that luck can determine if a person's action is good or bad, which seems unfair. Kant is wrong because Kant does not seriously consider the importance of consequences for moral assessments. In other words, Kant thinks that acting morally is risk-free.