Final answer:
Rousseau suggests that nature, society, and reason are the basis of morality, as they influence our moral sense, shape our behavior through laws and institutions, and guide us in developing meaningful relationships.
Step-by-step explanation:
Rousseau suggests that nature, society, and reason are the basis of morality. According to Rousseau, the social instincts and sympathy gained through natural selection form the first foundation of moral sense. Additionally, society and politics play a significant role in shaping morality, as laws and institutions can cultivate civic virtue and reinforce the good of the political community. Finally, reason and the virtues that allow individuals to achieve their goals and develop meaningful relationships also contribute to morality.