Mark resists Wither’s attempts to get to Jane because he resents Jane’s judgment. His fear of Jane judging him suggests that he (perhaps unknowingly) considers Jane to be morally superior to him in some way. In the meantime, Mark continues to be drawn in by the N.I.C.E.’s ideals of “purifying” humanity. This kind of language draws an explicit parallel to eugenics, a pseudoscience practiced by the Nazis that intended to “purify” humanity’s genetics.