Final answer:
Madison's opinion of the role of self-interest in one's life is realistic as it can be harnessed for the betterment of society and individuals can balance self-interest with concern for others.
Step-by-step explanation:
Madison's opinion of the role of self-interest in the conduct of one's life can be seen as realistic. He believed that self-interest could be harnessed to improve government and society, rather than leading to corruption.
A key aspect of Madison's argument is that self-interest does not necessarily mean acting only in one's own narrow self-interest. People can focus on their self-interest in economic decisions, such as negotiating for a raise, while also setting aside their narrow self-interest to help others in different aspects of life.
This understanding aligns with Adam Smith's perspective, who recognized that although individuals are often self-interested, they also possess principles that make them interested in the well-being of others.