Suppose I ask you what is a definition of a word. But to define it, you use the said word. Its perfectly natural, its a simple etymological mistake.
Mr Leith wants to talk to us about rhetoric. He does it with the voice of 1) infectious and humourous enthusiasm, 2) someone well versed in the subject. Rhetoric is defined as the art of persuasion. Mr Leith cannot help himself for the rest of the book to use rhetoric in helping to define rhetoric as we know it today. Its not the same level of etymological error as the above example but I wanted to point it out. Its a insider's joke he sets out himself: the very end of the introduction where he earlier gives the definition of rhetoric, he finishes with "let me persuade you"
I applaud him for it. He got me so worked up about rhetoric that I looked up all the terms on wikipedia and went away thinking "that was dull, complete and professional, but dull- the book was better"
The examples he gives us and the explanations and commentary that accompany them are more than proof of that. He starts off with dusty figures from Greece (which I found hard going) throws in some Champions of rhetoric (which includes the Devil, Abe Lincoln and Barack Obama, gee let's play odd man out). But along the way I learnt some deep things and more importantly I could relate to the concepts I had previously only associated with dead Greek philosophers and sophists. Logos, Pathos or Ethos anyone? This book does it in a paragraph and humourously so. To quote the Simpsons throughout the book is either a sign of populist outreach or genius.
This book also has had a disturbing side effect: previously a great speech was a moving one. But to go to the deepest molecular level of the persuasion with words, that was just intuitive. Now I know the magic, I wonder if I will be cynical about any great speech again.
The downfall is the subject matter itself. The golden definition of rhetoric took place in the dead and dusty reaches of history. I had to fight the association that I was reading about something dead and dusty. It is a fallacy easy to fall into.
Get this book if you are aspiring to give a speech, take part in debates, interested in the Greek classical tradition. The bonus is that you'll sound wiser- which is also a recognised part of rhetoric.