Thomas Jefferson had written in 1776 'all men are created equal, they are endowed by their creator, with certain unalienable rights'. That's natural law in a nutshell. How then could a country founded on these principles have permitted slavery and segregation to exist? The answer was that it couldn't, not without being untrue to its own ideals. I was looking for a way of thinking, a set of ideals, that fundamentally, at its core says slavery is wrong. At its core. Which Natural Law of course does.