Content Warning: Guts includes detailed portrayals of survival situations, including human fear, danger, injury, and death. The book includes graphic descriptions of hunting, trapping, fishing, and killing wild animals, as well as processing the bodies for food and tools.

At the heart of Guts is a thematic thread that weaves and binds the collection of anecdotes and stories into a cohesive collection: Survival is nature’s imperative, and man assures his survival in the wilderness through the acquisition of knowledge. However, Guts also suggests that man has lost the formerly hard-won, inherited information: “we have gone away from knowledge, away from knowing what something is really like” (Guts: 52). Humanity exists separate from nature and must “invent” survival again when he enters the wild, though he is now disadvantaged. Innate survival skills, once inherited and understood from generation to generation, have been lost due to advances in modern civilization. Paulsen values these forgotten skills and prioritizes humanity’s reconnection with a sense of survival and self-preservation.

Paulsen’s wilderness stories and vignettes are backward facing, reviewing the past for guidance: “Brian lived as they did in prehistoric times, and as I have done on occasion,” Paulsen writes (Guts: 137). He ventures into the forest to find a connection to nature and to the past.