What states that the government should play a limited role in the economy and that citizens would thrive when left to their own individual enterprise?

The concept you're referring to is often associated with classical liberalism or laissez-faire capitalism. It argues that the government should minimize its intervention in economic activities, allowing individuals and businesses to operate freely. Proponents believe that this leads to greater innovation, efficiency, and overall prosperity, as individuals are motivated by personal interests and competition. This philosophy emphasizes the importance of personal responsibility and the idea that a free market ultimately benefits society as a whole.