In The Human Condition, Hannah Arendt fascinatingly points out the derivation of our word "private," which of course is linked to "privation" and thus originally meant something like "deprived":
In ancient feeling the privative trait of privacy, indicated in the word itself, was all-important; it meant literally a state of being deprived of something, and even of the highest and most human of man's capacities. A man who lived only a private life, who like the slave was not permitted to enter the public realm, or like the barbarian had chosen not to establish such a realm, was not fully human. We no longer think primarily of deprivation when we use the word "privacy," and this is partly due to the enormous enrichment of the private sphere through modern individualism.
Arendt laments is that in modernity, we have exalted the role of privacy--private property, private life, private conscience, private faith--and forgotten just how deprived an existence lived outside the public, political realm really is. And of course, she blames a lot of this on Christianity. Obviously, she misunderstands the essence of Christianity, but perhaps, so has Christianity itself.