虽有佳肴，弗食，不知其旨也；虽有至道，弗学，不知其善也。
Although there are delicacies of the season, one cannot know their delicious flabors if one does not taste them; although there are ideal and perfect principles, one cannot know about their true significance if one does not learn them. (Used metaphorically to mean that genuine knowledge comes from practice.)
