Where does a speechwriter start when a brief lands on his or her desk? As Cicero tells us, the first task is to find out who will be in the forum. Know your audience.

Stepping onto the Moon on 21 July 1969, astronaut Neil Armstrong delivered one of the most remembered one-line speeches of all time. Even though he fluffed its delivery (leaving out a crucial indefinite article), it remains a memorable case of antithesis.

Armstrong’s words survive for one reason: the world, literally, was watching. Seen live by some 450 million television viewers, the astronaut had the undivided attention of what was, until that time, probably the biggest audience in human history. He held the 60 ultimate forum – humanity at the moment of its most stunning technological achievement. (And, as we shall see elsewhere in the book, the Apollo program provided the moments for some of the twentieth century’s most inspiring rhetoric.)

The moon landing speech illustrates the supreme importance for the orator of seizing the moment. Armstrong could justifiably have said nothing. In the frenzy following the rocket launch and preparation for the moonwalk, the question of what to say could easily have been overlooked. The technocrats at NASA may easily have regarded words as a distracting indulgence better left for the post-return-to-Earth press conference. This belief – that when all’s said and done words don’t really matter – is common but it is also a mistake. Even in politics, complex policy ideas launched without enough care given to their description and defence have a habit of not leaving the ground. Thankfully, Armstrong knew this. Somewhere between Earth and the Moon, he found the time to clear his mind and think of what to say. And it was brilliant.