Schools have the privilege and mission to develop our children's minds. Literacy and numeracy are an essential part of this process. Writing offers us tools to think about, and with, language. English script represents the sounds and grammar of the English language. When children understand how this script works, they learn new ways of thinking about language which they can use to increase their own knowledge of English and also to learn other languages. Texts freeze communication. They allow us to communicate across time and distance. When we think about texts, we learn about modes of communication which are distinct from those in oral language; we also have a new way in which to scrutinize our own reasoning. Mathematics offers us models to think about the world. Through mathematics, schools can open to children ways of thinking about the world which were invented by true geniuses in the course of history and which can become their own tools for thinking. When our children learn literacy and numeracy, we want them not simply to learn facts but also to encounter new objects of thought and tools for thinking. It is through this process that schools can develop children's minds.