The Pigs incorporates many different texts. I've provided them below, and links when possible, for anyone interested in reading more.
Bubolz, Bryan F., and Pete Simi. "Leaving the World of Hate: Life-Course Transitions and Self-Change."
Butler, Judith. The Force of Nonviolence.
Cavarero, Adriana. Relating Narratives: Storytelling and Selfhood.
Futrell, Robert, and Pete Simi. "The [Un]Surprising Alt-Right."
Hejinian, Lyn. "The Rejection of Closure."
Kallen, Horace. A Study of Liberty.
McCauley, Clark, and Sarah Moskalenko. "Mechanisms of Political Radicalization: Pathways Toward Terrorism."
Popper, Karl. The Open Society and Its Enemies.
Rorty, Richard. Contingency, Irony, and Solidarity.
Rukeyser, Muriel. The Life of Poetry.
Warnick, B.R., Kim, S.H. and Robinson, S. “Gun Violence and the Meaning of American Schools.”