Freedom (n.) The capacity of an individual or group for exchange of goods, services, knowledge or information with others, publicly or privately.
One person alone on a planet is not free.
Much has been written about freedom or the lack of it, but little on the somewhat fundamental question of why freedom actually matters, in terms of social physics. Occam's Razor suggests that all universal aspects of humanity, such as humour, dislike of mothers-in-law, and the desire for freedom, stem from pragmatic evolutionary reasons rather than collective whimsey or mass education. Freedom, thus, serves a socially beneficial purpose, and humans that strive for freedom (like those who strive to create distance between them and their mothers-in-law) tend to be more successful, genetically. What is then, that purpose? The key insight about freedom is that one man, alone on a planet, is not free. Freedom is not about walls and chains per-se, it is about the effect of those walls and chains on our need, as social animals, to be part of greater society. To take one example: much of Africa can correctly be described as a prison because so many Africans have close to zero capacity for exchange of goods, services, knowledge, or information with the greater world, due to difficult geography and artificial barriers.
Freedom requires privacy; the loss of privacy is directly responsible for the loss of freedom, because if an exchange cannot be private then it cannot happen optimally.