Confucianism is not a perfect philosophy, since it accepted and even reinforced certain societal injustices. Confucius incorporated traditional Chinese ancestor-worship into his system, which implied a degree of sacredness for ancestral practices. For this reason, Confucian principles perpetuated and exacerbated the oppression of women, who had no standing in the male-dominated family structure. Girls were considered an expense to their birth families, since they only became valuable when they married and bore sons for their new families. Female infanticide has been a problem throughout Chinese history, as was, until the last century, the practice of foot-binding, which rendered generations of Chinese women crippled and semi-mobile for the sake of what amounted to a fetish of Chinese fashion.

In the early millennia of their spread across the connected continents of Africa, Europe, and Asia, modern humans lived mobile lives as hunter-gatherers. According to archaeologists, many left traces of their presence in the area north of the Black Sea from about 80,000 to about 50,000 years ago. Although they may have favored certain locations for long periods of time, ancient people were forced to follow the herds they hunted and to seek new food sources when conditions changed. Climate changed very slowly, but the cycle of glaciation was a factor in human development; especially the most recent ice age which began about 36,000 years ago and lasted until about 11,000 years ago. This ice age displaced both animal and human populations, and also allowed some people to migrate to the Americas, as we will see.