This book is written by a man who was one of Maria Montessori's most intimate and long term work colleagues. Although her organization's leadership was handed down to her son, the author of the book is Mr. E.M. Standing.
The author is very well versed in the Montessori system of education and in the organizations designed to support it. Late in the book, he does inform readers that before he met Maria Montessori and became involved in her work he had taken up the study of Froebel.
The book is written objectively, but is most definitely supportive of Montessori education.