Herein lie some 44 pages that get right to the issues, well as far as one can get with this stuff. Though Dover gets into some weird epistemological territory when he abstracts on what's at hand, his abstractions make the more general and well-taken point that one ought to be careful with reconstructing these sorts of texts.
I find it more persuasive that he keeps finding new things when he reads Thucydides, than that everyone would, but one shouldn't fault someone for enthusiasm in their own work. At any rate, Dover's quite a bit more modest than his subject, and this I think is good. If you want a quick over-view over a quick cup of coffee, this book is your best bet.