Who is known for the idea that wealth should be used for philanthropy to benefit society?

The correct choice is Andrew Carnegie, who is widely recognized for advocating the idea that wealthy individuals have a moral obligation to use their fortunes for the greater good of society. This philosophy is articulated in Carnegie's essay "The Gospel of Wealth," published in 1889, where he argues that the rich should act as trustees for their wealth, benefitting society rather than hoarding their fortunes. Carnegie himself exemplified this belief through his extensive philanthropic efforts, funding libraries, educational institutions, and cultural organizations, thereby leaving a significant impact on American society.

Other figures listed, such as Rockefeller, also engaged in philanthropy, but Carnegie's work and writings specifically championed the concept of wealth as a means to uplift society. Herbert Spencer is known for his theories on social Darwinism, which do not align with the notion of philanthropy, and Russell Conwell is famous for his speech "Acres of Diamonds," promoting the idea that anyone can achieve wealth through hard work, rather than focusing on the obligation of the wealthy to give back to society. Therefore, Carnegie's strong advocacy for philanthropic responsibility sets him apart as the figure most associated with the idea of using wealth for societal benefit.