From Into the Wild, was Chris courageous or stupid?
This question is entirely a matter of personal opinion. Jon Krakauer claims to have tried to treat Chris as objectively as possible; he admits to personal bias and shows that Chris failed to properly prepare himself for the struggle of living in the wild. Krakauer notes in the introduction:
Some readers admired the boy immensely for his courage and noble ideals; others [thought] that he was a reckless idiot, a wacko, a narcissist who perished out of arrogance and stupidity -- and was undeserving of the considerable media attention he received.
(Krakauer, Into the Wild, Amazon.com)
Most opinions concerning Chris are based in judging his actions; was he correct to cut his family off from correspondence? Was he correct to refuse emotional connections with others? Was he correct to pit himself with little training and gear against the Alaskan wilderness? More importantly, were his goals and ideals worth the potential cost of his own life? Only Chris could have answered those questions, and only from a position of experience and hindsight; today, interpretations of his life are entirely subjective.
In the end, Chris made decisions and they cost him his life; his courage or stupidity (circumstantial stupidity, since he was very smart otherwise) is less important than the lessons the reader learns from reading about his life.
Chris was brave, courageous and determined. He wanted to explore life in a way that did not conform to his parent's expectation. They were fairly affluent and this helped his decision to cut all ties with them and mainstream society. He did this by abandoning his car and donating thousands of dollars in his savings into charity. Mainstream society teaches people that one must graduate high school, get a college education and get a high-paying job in order to be deemed successful. For other, like Chris, success was just being able to pursue the dream of wandering accross the continent.
Not many people are that willing to give up everything they own and losing contact with the people that they know in order to start anew. That is quite courageous.