Slavery is immoral. Why? Why do we hold this truth to be self-evident: that all men are created equal? Why are life, liberty, and the pursuit of happiness inalienable rights bestowed by our Creator? (“Declaration of Independence.” 1776.) Well, not all men are created equal. At least according to our founding fathers, African tribes, 18th century Europeans, ancient Romans and Greeks and… the Bible. In reality, slavery is not immoral from the point of view of humanity (also to be interpreted as that of America), but only for 150 years. Why then can we declare so firmly and undeniably that slavery is immoral? The answer lies in the writings of great political visionaries such as Solon, Aristotle, Cicero, Locke, Marx and Lincoln. Individually they all have different opinions on slavery. Taken together, however, their works reveal a timeline that shows how slavery evolved from an accepted habit to a depraved custom. The immorality of slavery is not outlined in a constitution. Slavery is immoral because time has proven it to be immoral. Since 2000 BC there have been laws protecting slaves. The Babylonian king Hammurabi promulgated the Code of Hammurabi during the 18th century BC. In the code of law Hammurabi outlined three distinct levels of criminality. The highest was the proverbial eye for an eye, which was the punishment for hurting a citizen. The second level was a fine of one gold mina if you injured a man who had been emancipated. Lowest on the totem pole was the crime committed against another man's slave. Payment for such a crime required half the value of the slave. If an ox had taken the slave's place under the same circumstances, the owner of the ox could have made no claim against the man who had injured him... in the middle of the paper... of the order. (Aristotle. “Politics.” Book I.vi.) The Romans had not yet reached these moral heights. Instead, the Romans enslaved all the peoples they conquered. Finally, after hundreds of years of uninhibited slavery, the Stoics dared to challenge the Roman philosophy of slavery. The Stoics firmly believed in an egalitarian social structure. This philosophy extended to the treatment of slaves and had a profound effect on Cicero. Cicero advocated “treating slaves as we should treat dependents.” (Cicero. “De Oficiis.” 1.41.) His theory of justice relied heavily on the phrase suum cuique (to each his own) and beating and mistreating slaves was unjustifiable because a Roman would never treat another Roman that way . (Cicero. “De Legibus 1.8.) This theory of “Do unto others as you would have them do unto you” is a great leap in morality compared to the old philosophies..