 A weak paternalist believes that it is legitimate to interfere with the means that agents choose to achieve their ends, if those means are likely to defeat those ends. So if a person really prefers safety to convenience then it is legitimate to force them to wear seatbelts. A strong paternalist believes that people may have mistaken, confused or irrational ends and it is legitimate to interfere to prevent them from achieving those ends. If a person really prefers the wind rustling through their hair to increased safety it is legitimate to make them wear helmets while motorcycling because their ends are irrational or mistaken. If one is a weak but not a strong paternalist we may only interfere with mistakes about the facts not with mistakes about values. So if a person tries to jump out of a window believing he will float gently to the ground we may restrain him. If he jumps because he believes that it is important to be spontaneous we may not.