This essay reflects upon certain aspects of Wittgenstein's own practices as a teacher. "Doing" philosophy always took priority for Wittgenstein, whether this was in oral or written form: it was important to show the deep puzzles in our language (and our culture and thinking) as a step toward dissolving them. In this respect, one can teach only as a guide; it is a matter of showing more than saying. Wittgenstein's approach suggests a model that I will call "tacit teaching". Tacit teaching refers to the many forms of informal instruction--some intentional, some unintentional, and some difficult to categorize simply as one or the other--by which skills, capacities, and dispositions are passed along within a domain of practice. Wittgenstein repeatedly uses the language of signposts, of wandering through a city, of being lost and finding one's way, of needing a guide, of learning how to go on by one's self, to refer to the complex web of knowledge and understanding that allows successful autonomous practice in some discipline: most pertinently, in the context of Wittgenstein's own teaching and writing, the discipline of doing philosophy, but with clear reference to teaching and learning in other complex and ill-structured domains as well.