This concern with the basic ...

This concern with the basic condition of freedom -- the absence of physical constraint -- is unquestionably necessary, but is not all that is necessary. It is perfectly possible for a man to be out of prison and yet not free -- to be under no physical constraint and yet to be a psychological captive, compelled to think, feel and act as the representatives of the national State, or of some private interest within the nation, want him to think, feel and act.
This concern with the basic condition of freedom -- the absence of physical constraint -- is unquestionably necessary, but is not all that is necessary. It is perfectly possible for a man to be out of prison and yet not free -- to be under no physical constraint and yet to be a psychological captive, compelled to think, feel and act as the representatives of the national State, or of some private interest within the nation, want him to think, feel and act.

Quotes from the same author

Experience is not what happens to you; it's what you do with what happens to you.
Experience is not what happens to a man. It is what a man does with what happens to him.
There is only one corner of the universe you can be certain of improving, and that's your own self.
Technological progress has merely provided us with more efficient means for going backwards.
No man ever dared to manifest his boredom so insolently as does a Siamese tomcat when he yawns in the face of his amorously importunate wife.