If they exert it not for good, they will for evil if they advance not knowledge, they will perpetuate ignorance.

The sentence frames human influence—especially the influence of education, public speech, and reform—as morally inescapable. Wright suggests that power, talent, or social authority cannot remain neutral: if it is not deliberately directed toward “good,” it will drift into “evil,” whether through active harm or passive complicity. The second clause sharpens the point by treating knowledge as a civic duty. To fail to advance understanding is not merely to stand still; it is to help sustain the conditions—ignorance, superstition, and manipulation—that enable oppression. The quote thus reads as a call to purposeful enlightenment and reform, consistent with Wright’s broader emphasis on reason, secular education, and social progress.