All of us are self-owning and self-determining.
All of us desire or strive to live according to our own will.
All of us are capable of employing reason.
These are the fundamental aspects of human nature that have not changed one bit over time. We must recognize that there are some constants as it regards our humanity, and we must seek to accommodate those constants as best as possible via our social organization. This idea that things are SOOOOO different than they were just because we're banging away on computers and flying around in jet-planes is just contemporary hubris. Fundamentally speaking, you aren't ANY different than the Roman gladiator or the American slave. We are all human and humans, no matter what time period they may live in, share the same fundamental nature or striving. That is what BINDS us.