What assumptions about human nature did Adam Smith make?

Adam Smith believed that ordinary human judgment was fairly sound across the board and that formal philosophical and political systems were not inherently superior. His theories about inherent human morality can be described as a unique form of moral sentimentalism developed out of moral judgements made by regular people.

Smith believed that human sympathy arose from imagining oneself in the circumstances of others, as opposed to experiencing the actual feelings of others. Smith also argued that sharing the feelings of others is a central drive in life and that concepts such as virtue arose from a continual process of adjustment to the feelings of people who are centrally involved with a set of circumstances.

Regarding political theory, Smith believed that the types of people who chose to go into politics tended to be inherently ill-suited for leading large numbers of people. He believed that vanity and a desire for fame and power were the primary motivators of the career politician and led to the politician feeling morally superior to others. He also believed that the politician's judgement was no better than that of the common person and that it might be worse, due to a lack of local knowledge and influence on the politician by mercantile interests.