Critic: Works of literature often present protagonists who scorn allegiance to their society and who advocate detachment rather than civic-mindedness.
Conclusion
Modern literature can damage individuals who appropriate an attitude of "I don't need to contribute to societal good" and damage society at large.
Evidence
Modern literature gives more sympathetic treatment (shows in a more positive light) protagonists who want to detach from society, rather than be engaged citizens.
Treating these recluses in this positive way suggests to readers that they should be unconcerned about contributing to society.
Evaluate
So the basic argument is that because modern literature "trains" its readers to think, "I should be less concerned about societal good", it damages the readers and it damages society.
Well, the second part makes more intuitive sense. If you get a bunch of modern lit readers to think, , that does seem like it would be damaging to society (this would only be good for society if people who wanted to help society did more harm than good).
But how does the first part work?
Why does it damage an individual person to say . I know that if I stopped being concerned about contributing to societal good, I would stop using Twitter (I mainly use it to get more informed about social problems), and that would probably benefit my mental health.
Goal
The big New Term in the conclusion is "damage individuals". How is the author assuming that modern literature damages individuals? By making them less concerned about societal good. So we're assuming something like, .
A correct answer could otherwise rule out an objection saying, .