Equality

During the Middle Ages, there were two important developments that affect the modern conception of equality. First, a natural law tradition developed around the notion that all humans, as God's creations, are owed certain rights and protections and that these natural laws cannot be altered by political associations or rulers. Thus we see in thinkers like St. Thomas Aquinas (c. 1224–1274) a rigorous defense of the principle that all people are due a certain minimal set of legal protections based solely on the fact of their humanity.

The second role the church played is more subtle, serving as a force for the gradual and irresistible movement toward a society organized around the fundamental fact of equality. The church took in members of the lower classes, gave them an education, allowed them to rise through the church hierarchy, and, given the important role church officials played in European state affairs, made it possible for individuals of humble origins to join the royal state's inner circle of advisers. It thus provided a clear counterexample to the notion that one is born to one's station, contributing to the decline of the view that society should be based on fundamental inequality in accordance with one's birth (Tocqueville, pp. 9–10).

As the Protestant Reformation approached, Christian humanists set out to understand the precise meaning of the founding texts (the Bible and doctrines of the early church fathers). This, combined with the advent of the printing press and the widespread publication of the Bible and other writings in the common tongues of the people, created an atmosphere in which intense scrutiny of and debate over the meaning of Christian doctrine was considered appropriate, and individuals came to see themselves as capable of judging doctrine for themselves based on their knowledge and skills. This culminated in Martin Luther's (1483–1546) statement, in a debate with Johann Eck, that the Bible, not the pope or church councils, is the sole guide for human conscience. It is a short leap from these views to the modern liberal notion that individuals, with no need of an intermediary or authority to tell them what to think, can best determine their own beliefs and interests. In the Reformation era, individuals became radically equal in their capacities to judge matters for themselves.