Robert Macfarlane, Mountains of the Mind: A History of a Fascination

"As de Saussure said, risk-taking brings with it its own reward: it keeps a "continual agitation alive" in the heart. Hope, fear. Hope, fear - this is the fundamental rhythm of mountaineering. Life, it frequently seems in the mountains, is more intensely lived the closer one gets to its extinction: we never feel so alive as when we have nearly died."