This is a short and profound book. I've read it four times and it gets better every time. In fact it is the only book that I have ever read four times. It has changed my views on free speech for ever.
What's the core argument in the book? Well, one cannot explain it in a short review, which is always a good sign (if one could, what would be the point of reading an entire book?). But in a nutshell, it is a defense of unlimited free speech. I say *unlimited* because while most people see value in free speech, most people would also argue that there have to be some limits (hate speech, for example, or denying the holocaust). This makes intuitive sense, and this was also my point of view - before reading this book. The book has convinced me that the power of free speech lies EXACTLY in the ability to express opposing views, no matter what they are. (This is a gross oversimplification of the book - you really have to read it).
This is not a political book - it is a philosophical book, but one that doesn't require any previous formal philosophical education. Anyone can, and I think everyone should read it.
The author eloquently and convincingly advocates for unfettered and unrestricted free speech, regardless of its potential to offend, preferring to allow the machine of social opinion dictate what is accepted as truth and what is cast aside as fringe nonsense, rather than allowing government and legislation decide what can be said or believed.