His most famous remark on slavery is found in "Candide", where the hero is horrified to learn "at what price we eat sugar in Europe" after coming across a slave in French Guiana who has been mutilated for escaping, who opines that, if all human beings have common origins as the Bible taught, it makes them cousins, concluding that "no one could treat their relatives more horribly". Elsewhere, he wrote caustically about "whites and Christians proceed to purchase negroes cheaply, in order to sell them dear in America". Voltaire has been accused of supporting the slave trade as per a letter attributed to him, although it has been suggested that this letter is a forgery "since no satisfying source attests to the letter's existence."