I think the underlying theme of his show and the book can be summed up as "be prudently cautious but resourceful and never give up".

Just saw the new Sierra Nevada episode, where he makes a trap out of his guitar in addition to Paiute deadfalls from rocks and sticks. None of them caught anything - and in fact one of the deadfalls failed from being set up improperly - and the fact that he shows that, along with his thought processes and how he learns - is fantastic.