Spiritualism And The New Psychology

My object in writing this book is to present an explanation of so-called
occult phenomena concerning which credulity is still as busy as in the
days of witchcraft. The producers of these phenomena have been exposed
efficiently and often, but their supporters are as active as ever, and
show a simple faith which is more convincing than any argument.
Moreover, the producers themselves--mediums, clairvoyants,
water-diviners, seers, or whatever they may be--are sometimes of such
apparent honesty and simplicity that disbelief seems almost a sacrilege;
therefore part of my aim is to show how a man believing firmly in his
own honesty may yet practise elaborate trickery and deceit.