Slavery has continued to exist as an institution throughout human history and still exists in many parts of the world. Slavery means the loss of free will, indicates that violence will be used to maintain control over the slave, and determines that the slave will be exploited, normally in some type of economic activity, but possibly for sexual purposes or even as an object of conspicuous consumption ” (_____). Nearly every culture and historical period has recognized slavery; it has been known and used in every time and place until today. Modern and ancient slavery are largely different in several traits such as a slave's origins, work, and freedom. Throughout history, the origin of slavery is viewed differently. The history of slaves covers a system in which one human being is the property of another; people can be bought and sold like property. Slavery was recognized and used in a variety of ancient civilizations such as Ancient Egypt and Ancient Greece. In the ancient world there were different intentions to become slaves. Evidence of slavery dates back to the 18th century, with the great builder pharaoh, Thutmose III, turning non-combatant captives into slaves: "they returned from a victorious...with nearly 90,000 captives, who were afterwards transformed into slaves" (Slavery ). In proportion to the Egyptian population at the time, 90,000 prisoners was considered a large number of captured citizens, according to Egyptologist, art historian and author Cyril Aldred, "The main source of slaves were prisoners of war." With respect to modern slavery, which was considered socially unacceptable, the ancient Greek philosophers “attempted to justify Greek slavery” (philosophers). /27-million-modern-slaves-what-to-do-to-prevent-it/>."Statistics on modern slavery." Abolition Media RSS, nd Web November 26, 2013. “Slavery in Ancient Civilization: Egypt.” Slavery in ancient Egyptian civilizations. Np, nd Web. November 26, 2013. “Philosophers Justifying Ancient Greek Slavery.” BBC News. BBC and Web. 25 November 2013. "Modern slavery". BBC News. BBC and Web. 26 November 2013. "Facts about human trafficking | Sexual slavery and trafficking | Soroptimist." Facts about human trafficking | Sexual slavery and trafficking | Soroptimist. Np, nd Web. November 25. 2013.