... remembering, recognising, understanding, learning, proving, explaining,communicating, referring, describing, interpreting, imagining, creating, deliberating, choosing, acting,testing, verifying, and so ... can be changed in many ways. The invention of painting and drawing permitted newthoughts in the processes of creating and interpreting pictures. The invention of speaking and writingalso permitted ... teaching, as well as solving old problems in philosophy of mathematics. In the remainder of this chapter I shall attempt to present, in bold outline, some of the main themes of the computer revolution, ...