ABSTRACT
On parle dans sa propre langue, on écrit en langue étrangère. Jean-Paul Sartre, Paroles
With this chapter, I start to look at the second main theme of this book, namely aspects of written mathematical language. What are some of the differences between spoken and written language alluded to in the Preface, and how do they affect written mathematics? Speech frequently fulfils a more direct communica tive function, but because speech is invisible, it does not persist except as memories of what someone has said. Its intangible quality renders speech less permanent, and hence more readily altered and revised.
