Reginald Scot Esq. was one of those learned gentleman who set out to write a book to show witchcraft as a deception.
It's possible he's still spinning in his grave, since despite his initial aim of rationalising magic and magical practice---denouncing it by revealing the tricks and skills of charlatans and the like---according to Owen Davies (an academic who has produced many books on magic and its historical use):
"Scot produced what amounted to the first grimoire printed in the English language ... and unwittingly ended up democratizing ritual magic rather than undermining it."
Something of an error of judgement there.
The main issue seems to have been his detailed accounts of magic spells, prayers, charms, talismans, and ... relevant to A Bagful of Dragon, a description of how to trap a spirit in a crystal.
I, for one, like to look at its pages. I love the highly readable reprint of this first edition from 1584 and find that if you read it quite quickly, the unfamiliar spellings and grammar seem to merge into comprehension reasonably quickly.