Bernard of Clairvaux
Believe, my dear friend, to my own experience. You will learns much more in the woods than in books. Trees and stones will teach you things that you would not know elsewhere, you will see for yourself that honey can be extracted from stones and oil from the hardest rocks. Do you not know that joy is distilled from our mountains…?
Epistola CVI, sect. 2; from Bernard of Clairvaux to Hery Murdach, futur abbot of Wells, England.
translation from Edward Churton The Early English Church ( 1841) p. 324