Rousseau argues that human inequality began with the institution of property, but before one person could declare something exclusively theirs, humanity needed to develop ideas that prepared them to leave their natural state. Human beings began by responding to the dictates of nature, but over time different peoples would encounter nature in profoundly different ways as they spread over the globe. Some would live in cold regions, others in the tropics. Some would live near water and learn to fish others could traverse mountains and eventually would have learned to manipulate fire. As people became more skilled in dealing with the challenges of their environment, some would eventually become aware that they were better at those skills than others and would feel the first stirrings of pride. At this point, they would be able to draw a distinction between their interest and the good of the whole, based on an assessment of what they can achieve through skills versus what they need from the group. Rousseau notes that in the matter of hunting a deer, the individual will still need the group, but if a hare runs along, they might choose to catch it for themselves.

Inequality at first developed very slowly, but each new milestone increased the pace of development.