I've occasionally read up on the ancient Greek philosophers, and it's not an easy subject. This work, though I would have liked to see another twenty pages devoted to each of Plato and Aristotle, concisely explains the basic ideas behind the major figures of that time. Though Guthrie obviously had to be extremely selective in such a small volume, the result is clear and concise, and also quite helpful.
Of particular note is that Guthrie paid close attention to the definition of terms. Rather than quote the relevant philosopher, and then explain what was meant in the passage, he pointed out right in the first chapter that translating two and a half millennium old Greek into modern English is fraught with peril. For this reason he always introduces each important Greek word with a good explanation of just what it meant before continuing with the discussion. This, I think, is particularly well done. In short, I would say Guthrie's The Greek Philosophers is a fine introduction to the field.
W.K.C. Guthrie, the famous historian, shows us in this book the essence of Greek philosophy, travelling through the minds of the pre-soctratic thinkers and the birth in Athens of what would become the most unique trio of Wisdom-lovers in history. Prof. Guthrie's account is outstanding and far more profound than most of our century's writers.