In the Priorat, the Carthusians had two basic rules for growing grapes: Plant in dry soil that is not too cold because otherwise the grapes do not mature, and do not plant in soil that is too warm because the grapes will ripen too soon. They were right, of course. Traditional farming practices like this were handed down both orally and by example. They have been confirmed by observation in the laboratory of life. 

Perhaps the wisdom of these practices comes from a time when humans were more connected with nature. Time has formed a relationship that provides an instinct about how to respond to the variables nature delivers. Ask most old-timers why they do something and they shrug their shoulders. They have come to know the vines, to recognize when they are suffering or critters have been snacking on them. Every herb and tree that grows around the vineyard has a part in the story. 

People have been farming by the alignment of the stars since civilization began. Their practices come before science, and then science proves them right. Wine moves better with the help of gravity. In the Priorat mules work best on the steep slopes. The use of ropes or ladders is advised. These are traditions that have evolved with the demands of the land. They are second nature, rather than something read in a book. 

— Adapted from Ethos Priorat, a book by Elizabeth Hecker