What life affirming aspects are present in Chris McCandless's actions in Into the Wild?
There are several elements of what McCandless did that could be considered life-affirming. Through his rejection of most material possessions and his adventures in the wilderness, Chris seeks to find a kind of "spiritual reality" and freedom that transcends the reality of our material world. Whether or not McCandless ever accomplishes this is open to debate, but I'm inclined to believe he did not. His burning of his money, his refusal to possess anything he could not carry, his focus on gaining enlightenment are all expressions of his goal of achieving overall happiness in life despite to preconceived notions of larger society.
McCandless was reckless and foolhearty in his great Alaskan adventure. As noble and inspiring as the idea of his quest might be, his preparation and lack of knowledge create a situation ripe for disaster. Spiritual reality is a lofty goal, but what is it worth if you have no one to share it with? It reminds me of the old conundrum: If a tree falls in the forest but no one is around to hear it, does it make a sound?