Liz Truss was spot-on in arguing that the only way in which a state can flourish is by combining low taxes with economic growth. But she failed to persuade her audience that she knew how this could be achieved. If only Dr Kwarteng, a classicist, had drawn her attention to Aristotle’s Art of Rhetoric (4th century bc), the first full analysis of the means of persuasion, the day and her career would have been saved.

First, Aristotle defined two general types of persuasive proof. One he called ‘artistic’, because it depended upon human ingenuity, the other ‘non-artistic’, because it derived from pre-existing evidence, e.g. witness statements, written contracts, etc. Then he identified three specific areas relevant to successful persuasion: first, the character of the speaker and the contribution his credibility could make (êthos, which he calls ‘the most authoritative form of persuasion’); second, the favourable emotional reactions (pathos) that the speaker could legitimately arouse in his audience; and third, the ‘true or apparently true’ arguments (logos) for his case that the speaker could invent. On all these counts – self-presentation, understanding of the mindset of her audience and the solid reasons for believing that she could deliver what she promised – Ms Truss clearly failed. She seemed to think her personal determination to succeed was enough to win the argument.

How simple it would have been to correct that error. All she had to do was produce her single piece of ‘non-artistic’ evidence, i.e. the OBR’s analysis of her proposals. Her promise to do so in two months’ time simply shot her credibility to pieces. This final failure perfectly exemplified the lesser-known, fourth Aristotelian aid to persuasion: that your speech is delivered at the right moment (kairos) to ensure its favourable reception. To reveal plans so admirably ambitious, but subjected to no serious second-party scrutiny, gave the Blob an open goal.

From Ms Truss to Mistrust in a single calamitous speech…