No amount of energy will take the place of thought. A strenuous life with its eyes shut is a kind of wild insanity. – Henry Van Dyke

…the thoughtful excitement of lonely rambles, of gardening, and of other like occupations, where the mind has leisure to must during the healthful activity of the body, with the fresh and wakeful breezes blowing round it… – Augustus William Hare and Julius Charles Hare, Guesses at Truth, by Two Brothers

The thoughts that come often unsought, and, as it were, drop into the mind, are commonly the most valuable of any we have. – John Locke, 16 May 1699