If liberalism is "about" anything if it has, or has had, any actual philosophical content as a set of ideas it is about freedom. Yet freedom, sitting as a word by itself, does not in fact have much content. It draws its actual content from context, and in context there are broadly two sorts of freedom: freedom *to and freedom *from. I may have, or wish to have, freedom to do various things: to learn to play the saxophone, to marry the person of my choice, to live with that person without marrying, to worship according to my conscience, to pursue happiness.
I may also have, or at any rate wish to have, freedom from certain things: from being robbed and killed, from being arrested on a policeman's whim, from starving amid plenty, from being forced to marry a particular person, from being compelled to worship in a way that violates my conscience, from being kidnapped, hauled to another continent, and put to work in cotton fields.
On one level, every freedom to can be expressed as a freedom from, and vice versa. If I have freedom to learn the saxophone, the implication is that I have freedom from being forbidden to learn it. If I have freedom from being forced to marry a particular person, I implicitly have freedom to marry someone else of my choosing. (I might be forbidden to marry anyone, but freedom from that implies freedom to marry someone). However, freedom from seems to also have a certain priority over freedom to, in that the former is a precondition of the latter. If I have no freedom *from being enslaved, I don't have any freedom *to do anything. Indeed, freedom to implies freedom to *not, which is a form of freedom from. If I am compelled to practice the saxophone, it is meaningless to say I am free to do so. If I am compelled to marry a particular person even the person I would have chosen anyway the marriage is not an exercise of freedom.
It is not surprising, then, that liberalism, as ...