We explore in this chapter the notion of liberty that will, in the end, allow us to better understand it in a world where individuals are innately social and where liberty cannot be presumed to be equally distributed. To this end, we create a sufficiently broad framework that also allows us to compare and contrast different conceptions of liberty and examine their logical relationships with different principles of social organisation. We propose here that liberty is comprised of two fundamental elements: freedom and sovereignty. We also suppose that freedoms, sovereignty, and subsequently, liberty, are all continuous concepts which allow us to consider equal measures of liberty that are comprised of different degrees of its constituents. By creating both a continuous concept of liberty as well as by juxtaposing it against a continuous constraint depicting varying social institutions defined in terms of the same parameters, we are able to identify an optimal notion of liberty for which there is a logically commensurate social structure. This too is part of what I call the economics of political philosophy in that, that we claim that in the end, for a set of values to be sustainable it must be at least logically consistent with social institutions that can uphold it. What we borrow here from economics is the notion that a certain normative position can be identified as a solution to an optimisation problem in a space where all possible alternatives may potentially reside. It also allows us to associate different premises on human nature with variations on the concept of liberty and subsequently, with variations on the kind of social institutions that may help facilitate them.