Keep close to Nature’s heart... and break clear away, once in awhile, and climb a mountain or spend a week in the woods. Wash your spirit clean.

In this exhortation, Muir frames wilderness not as a luxury but as a spiritual necessity. “Keep close to Nature’s heart” suggests an intimate, ongoing relationship with the nonhuman world—one that counters the deadening effects of routine, industrial life, and social pressures. The advice to “break clear away” implies that periodic, deliberate withdrawal into mountains or forests can restore clarity and moral balance. “Wash your spirit clean” casts wild nature as a kind of cleansing medium: immersion in it renews perception, reorders priorities, and reawakens humility and wonder. The quote encapsulates Muir’s broader conservation ethic, where protecting wild places matters because they sustain human inner life as well as ecological health.