“An important component in the history of knowledge is the development of techniques that increase the potency of “words and diagrams.” What is true historically is also true for the individual: An important part of becoming a good learner is learning how to push out the frontier of what we can express with words. From this point of view the question about the bicycle is not whether or not one can “tell” someone “in full” how to ride but rather what can be done to improve our ability to communicate with others (and with ourselves in internal dialogues)”