… is from page 26 of the 2006 Liberty Fund edition of Ludwig von Mises’s 1956 volume, The Anti-capitalistic Mentality (available free-of-charge on-line here):
Nobody is needy in the market economy because of the fact that some people are rich. The riches of the rich are not the cause of the poverty of anybody. The process that makes some people rich is, on the contrary, the corollary of the process that improves many peoples’ want satisfaction. The entrepreneurs, the capitalists and the technologists prosper as far as they succeed in best supplying the consumers.