Liberty / Freedom; the same thing only different?

For some time now, I've sensed that liberty and freedom have different meanings. Differences, that even after exploration, I could not truly grasp and could not, therefore, articulate. Today, I inadvertently came across an article published in the New York Times, 3/4/2003, written by Geoffrey Nunberg, that opened the door for me. The piece isn't necessarily an end in itself as regards the two concepts these words are intended to convey, but it broke the log jam in my thinking, allowing me to discern, and consider more clearly their differentiating qualities. Rather than hold forth on what the article said, I invite you to read it for yourself.

http://is.gd/1hbCY