The book is billed as a first aid kit of clear thinking.
This book is a highly accessible field guide to spotting and avoiding bad argumentation. There are so many ways that argumentation and thinking can go wrong. Among those that Stebbing discusses are poor choices of language and insufficient attention to meaning and definition. Another is what she called “potted thinking,” which is the mindless circulation of worn truisms that have the appearance of being reasoned statements and contributions but are really so devoid of actual, intentional application that they add very little sustenance to a discussion. Potted thinking is to actual thinking what potted meat is to actual meat (it’s where she got the term). She also warns of propaganda, emotional thinking, poor and misleading illustrations and analogies, exaggeration, appeals to the self-evidence of numbers, and digression.
She also has some hard words for charismatic speakers who spend more time “persuading” than they do “convincing.” The difference is that persuasion is a form of sophistry whereby weak arguments are inflated by moving audiences to beliefs based not on the soundness of the arguments but on the appeal of the presentation. Convincing an audience requires presenting them with the facts, completely, and without distortion. With guidance and time, an audience will work through sound arguments and become convinced of the truth. I understand and am maybe sympathetic to this view of rhetoric as being manipulative but 1) rhetoric is essential to argumentation, and 2) even the most transparent and logical argumentation is rhetorical in that it relies on first moving the audience to accept a particular way of understanding the relationship between statements and the conditions of the world that allow those statements to be true.
Stebbing is an interesting but overlooked historical figure. She can be placed squarely in the tradition of analytic philosophy, having been trained, in part, at Cambridge. She was also the first woman in the UK to have been appointed a full professor in philosophy at Bedford College. She was active between WWI and WWII and was apparently well respected in her time.