Which philosopher is known for the idea that individuals are inherently self-interested?

The philosopher known for the idea that individuals are inherently self-interested is Hobbes. He is famous for his social contract theory presented in his work "Leviathan," where he argues that in a state of nature, individuals act primarily out of self-interest and that this leads to a state of constant conflict. Hobbes believed that to escape this chaos, individuals consent to surrender some of their freedoms to a central authority in exchange for security and order, highlighting the role of self-interest in justifying the existence of government.

Locke, on the other hand, saw individuals as rational beings who could govern themselves, believing in natural rights and the idea that people are generally cooperative rather than solely self-interested. Montesquieu focused on the separation of powers within government to avoid tyranny and did not emphasize self-interest as a core nature of humanity. Tocqueville analyzed American society and the nature of democracy but did not primarily focus on self-interest as defining human behavior.