What I know of the divine sciences and of Holy Scripture I learned in woods and fields, by prayer and meditation. I have had no other masters than the beeches and oaks.
— St. Bernard of Clairvaux
I can easily imagine Henry David Thoreau making this statement. It is somewhat surprising to read it from a saint of the Christian tradition.
However, St. Augustine spoke of there being two books of scripture, The Bible and Nature. This was also a view of the Celtic Christians. Both Augustine and the Celts acknowledged one could learn as much about God from God's creation as from the Book of Books.
Incidentally, this is the Bernard for whom the rescue dog was named.