"Liberty is the possibility of doubting, of making a mistake,... of searching and experimenting,... of saying No to any authority - literary, artistic, philosophical, religious, social, and even political." ~Ignazio Silone, The God That Failed, 1950
Of all the quotes pertaining to the ideals of Liberty that I have ever read, this one, in my humble opinion, is by far the best. It tells me that true Liberty is the inherent right of each individual to refuse any dominion or rule over his mind, body, or soul.
Feel free to add your own opinions....