What is the theme in The Wild Muir: Twenty-two of John Muir's Greatest Adventures by John Muir?

Exploration is another theme in the book. John Muir is one of history's great mountaineers. He single-handedly explores many mountain territories that have never been explored before. He carefully explores the Yosemite Valley and Yosemite National Park is created due to his efforts. Muir often engagse in exploratory ventures simply to see new things. For instance, he climbsan ice cone just to look hundreds of feet into the open core. He engages in two very dangerous climbs of some of the tallest mountains in the area, Mount Shasta and Mount Ritter. The desire to climb Mount Shasta almost kills him.