There has never been a major civilization that in the beginning, or through the entirety of its existence, has not been divided into two classes: the master class and the slave class. Ancient Greece was a great slave society. Ancient Rome was an even greater slave society. The greatest of all slave societies was the Roman Empire which at its peak had conquered and enslaved much of Europe, and parts of Africa and Asia. The paradox is that while these civilizations were making use of slavery, their master class made significant advancements in developing the ideas of liberty, rationality, and individualism. On the relevance of masters and slaves in society, I can draw three inferences: first, the existence of slaves and their masters is a necessary condition for mankind to create new civilizations; second, the existence of the slave class does not hinder the master class from developing ideas of liberty, rationality, and individualism; third, all of history can be understood as the dialectics of collaboration and conflict between mastery and slavery.