Kant and utilitarianism

Kant and the utilitarians offer the two great modern rivals in ethics: Kant judges an act by whether its maxim can be a universal law and whether it treats persons as ends, while utilitarianism judges it by whether it produces the greatest happiness. For example, Kant would forbid lying even to a would-be murderer at the door, because the maxim of lying cannot be universalised, whereas a utilitarian would permit the lie if it prevents a murder and maximises overall welfare.