In this article, I try to embark on an understanding of the work that the concept of freedom does, by distinguishing it from the concept of power. When we are interested in our power, we are interested in what we are able (and not able) to do; it is plausible to think that when we are interested in freedom, we are interested in something else. The article is largely concerned with looking for this 'something else'. I suggest that freedom differs from power in focusing on the constraints that we are (or are not) under. When we are interested in freedom, the importance of these constraints is not particularly that they stop us doing things, because that is covered by considering our powers. I suggest that the constraints are important - if they are important at all - because some constraints insult our dignity. This suggests an alternative approach to the current focus on freedom as a property of actions: that of freedom as a property of persons. This idea is explored and defended. In a final section on republican freedom, I argue, against Pettit, that there is no distinctive concept of republican freedom (as distinct from the standard liberal understanding of freedom); but that there is a different - and a highly attractive - political theory present in republicanism.