This book is a landmark in its topic, can't argue with that. However, I have two remarks (not critics): (1) the book has been written in an era that it quite different from the one we are living in today. That says, the advise given doesn't suit quite well with the type of concentration we are concerned with, namely, era of the Internet, social network explosion, technology diversion, bro-science, etc. (2) the book's focus is more on why concentration is good (power of concentration), but not that much, or at least as much as one might firstly image, on how to increase the concentration. So, if you are looking for a book that is 90% teaching you how to improve your concentration and fight distraction, then you probably are better off with other works.