Knowing how and knowing that
This chapter considers what might appear a surprising connection: a positive relation between tacit knowledge and language. The stress on balancing conceptual structure with both context-dependence and practical knowledge addresses a potential worry that knowledge has to have content. Tacit knowledge stands opposed to the principle of codifiability (PC) but not the principle of articulacy (PA). Thus, in general, tacit knowledge cannot be conveyed by situation-i ndependent linguistic instruction. The chapter focuses on the work of the sociologist Harry Collins. Collins and Robert Evans argue, partly on the basis of experiment, that mastery of the language of a practice can carry a form of "practical understanding" that stops short of practical ability. While echoes of it can be overheard in less than optimal circumstances, practical knowledge can be fully demonstrated by skilled teachers to pupils with the right capacities to grasp what is articulated.