…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

No problem can withstand the assault of sustained thinking. – Voltaire

Invest a few moments in thinking. It will pay good interest. – Author Unknown

Irons rusts from disuse, stagnant water loses its purity and in cold weather becomes frozen; even so does inaction sap the vigor of the mind. – Leonardo da Vinci, Notebooks, 1508