?The Arya Samaj? is a book by Lala Lajpat Rai, aimed to state the position of Arya Samaj in the words of its leaders, who are the best exponents of its doctrine and its views. ?The Arya Samaj is undoubtedly a potent spiritual ferment in Punjab, combining what may be called a Protestant reformation of the secular abuses and legendary accretions of orthodox Hinduism with a Puritan simplification of life and a Roundhead insistence on the development of Indian intellectual life and thought. Of this movement and in this social service, Mr. Lajpat Rai has been long a leader. He adds a new service to us all by bringing its history, its aims and its achievement to the notice of the ever-growing English-reading public, not only in the United Kingdom and America, but also in India and Japan.?