This book is conveniently split into two halves. The first part contains Rev Hannah's opinions why a Christian cannot be a Freemason. Well, he was entitled to his views but many Vicars, Bishops, and other Churchmen have no difficulty being "On the Square" and even some Roman Catholic clergy, as Hannah himself became, are secretly Freemasons as their church, NOT The Craft, would bar them. The second half of "Darkness Visible" is first class, an accurate description of Masonic Ritual free of the sensationalism and false embelishments of both earlier and later books on this subjects such as the ridiculous and inaccurate "The Brotherhood". I commend "Darkness Visible" to both Brethren and non-Masons wishing to make a serious study of The Craft but take the authors adverse opinions and theological reasoning under advisement!