This book is a reformatted edition of the original work as it first appeared in the English language in the year 1622. St. Peter Canisius of the Company of Jesus originally composed his catechism in Latin as an easy handbook for people ""of a simpler sort."" It's use by the Jesuit fathers in Germany during the time of the Protestant Revolution was instrumental in saving half of that country from the slavery of disbelief. St. Peter Canisius' catechism, or ""Sum of Christian Doctrine"", has been translated into over 500 languages, but is only just recently to be found in carefully updated, modern English.