 Those who say that drawing a line between adults and children in respect of their possession of rights is arbitrary may mean different things. To deny that different capacities are progressively acquired at different ages is implausible. To insist that drawing a line as such is wrong ignores the point of doing so, and recourse to the alternative of a competency test is not appropriate or practicable. On the standard view children have welfare but not liberty rights, whereas adults have both. Adults also have the right that their childhood selves shall grow up to be adults of a certain sort. Children do not have an interest in remaining in childhood.