"Everybody wants to be be... closer to free" --BoDeans "Closer to Free"
We often speak of freedom and liberty as if they are quantities. But what does it mean to be "more free?"
Off hand, quantifying freedom is going to be a rather difficult task, but it should be possible to develop bounds, maybe an estimator and perhaps a clear set of units that freedom should be measured in.
In some sense, freedom is a physical thing. One useful, (quasi)physical definition for freedom is "the number of states an individual can safely be in." This leads me to intuit that the freedom of society should resemble temperature, a macrostate that combines the freedom of the individual members. Of course, some states are more desirable or more beneficial than others, so there is probably some sort of weighting between the states. Also, it's not clear to me how to discretize or partition (since it's got a thermodynamical flavor) the state space. Or even what the space should look like. (Should it consist of position and velocity? Individual wealth and health? Energy and power available to the individual? The set of strings describing the individuals actions? Etc, etc.)
Since freedom clearly has at least some physical meaning, we should be able to at least come up with a decent definition for "physical freedom." "Physical liberty" is preferable, I think, since freedom already has so many uses in discussing physical systems.