Translation: Feng Guifen's comments on English (1861) In Evan Osnos's book "Age of Ambition" there's an excerpt that says:


  This was a sharp reversal from the past. In nineteenth-century China, English was held in contempt as the language of the middlemen who dealt with foreign traders. “These men are generally frivolous rascals and loafers in the cities and are despised in their villages and communities,” the reformist scholar Feng Guifen wrote in 1861. But Feng knew that China needed English for diplomatic purposes, and he called for the creation of special language schools. “There are many brilliant people in China; there must be some who can learn from the barbarians and surpass them,” he wrote. 


It seems that it is from 冯桂芬's《校邠庐抗议》where he talks a lot about 西学 and whatnot - but I might be wrong.

What was the original Chinese of:

“These men are generally frivolous rascals and loafers in the cities and are despised in their villages and communities,” 

And 

“There are many brilliant people in China; there must be some who can learn from the barbarians and surpass them,”
the internet archive is your friend :)

it's in the book "校邠廬抗議", 卷下﹒采西學議 (p66, p69)

https://archive.org/details/02092023.cn

There are many brilliant people in China; there must be some who can learn from the barbarians and surpass them

中國多秀民﹒必有出於夷而轉勝於夷者



These men are generally frivolous rascals and loafers in the cities and are despised in their villages and communities,

其人率皆市井佻達游閒﹒不齒鄉里



it seems that your book "age of ambition" is quite interesting :)