Introduction: But what if in order to save one’s life one has to kill another person? In some cases that is obviously permissible. In a case I will call Villainous Aggressor, you are standing in a meadow, innocently minding your own business, and a truck suddenly heads toward you. You try to sidestep the truck, but it turns as you turn. Now you can see the driver: he is a man you know has long hated you. What to do? You cannot outrun the truck. Fortunately, this is not pure nightmare: you just happen to have an antitank gun with you, and can blow up the truck. Of course, if you do this you will kill the driver, but that does not matter; it is morally permissible for you to blow up the truck, driver and all, in defense of your life.
Comment: The text discusses permissible and excusable self-defence reactions towards different types of aggressors. It is useful in teaching on issues involving the doctrine of double effect.