This was clearly intended as a companion to the Fontana Dictionary of Modern Thought (also well worth getting). The dictionary of modern thought is a well organised and authoritative guide to modern thought in all fields. The dictionary of modern thinkers essentially does the same, but is arranged by named thinker and not topic. The two complement one another well. All the great thinkers of recent times are hear, as well as many you probably wouldn't have heard of. Obviously doesn't include very recent thinkers worthy of note (are there any?) because of the date of publication.