How can you explain that you need to know that the trees are still there, and the hills and the sky? Anyone knows they are. How can you say it is time your pulse responded to another rhythm, the rhythm of the day and the season instead of the hour and the minute? No, you cannot explain. So you walk. – Author unknown, from New York Times editorial, “The Walk,” 25 October 1967

We ought to take outdoor walks, to refresh and raise our spirits by deep breathing in the open air. – Lucius Annaeus Seneca, “On Tranquillity of Mind”

I like to walk, touch living Mother Earth—bare feet best, and thrill every step. Used to envy happy reptiles that had advantage of so much body in contact with earth, bosom to bosom. [We] live with our heels as well as head and most of our pleasure comes in that way. – John Muir, quoted in To Yosemite and Beyond: Writings from the Years 1863–