An updated Indian Edition, originally published by Edizioni “Orientalia Christiana”, Pontifical Oriental Institute, Rome, Italy. The author has very recently updated the contents of the book. Pope John Paul II has beautifully stated that the church breathes fully with two lungs, one Eastern and one Western. The recognition of this basic truth about the Church has contributed very much towards a comprehensive ecclesiology. However, despite the recent progress in mutual understanding between the Churches of the East and West, there still remains much ignorance and prejudice that needs to be overcome by proper education and change of heart.