Yes. There are many historical examples of fields which are simply complete nonsense, with some practitioners who are well-intentioned and wrong and others who are just blatant charlatans. Alchemy is one obvious example. More controversially, psychotherapy in our own era probably qualifies (http://www.amazon.com/House-Cards-Robyn-Dawes/dp/0684830914).
Yes. There are many historical examples of fields which are simply complete nonsense, with some practitioners who are well-intentioned and wrong and others who are just blatant charlatans. Alchemy is one obvious example. More controversially, psychotherapy in our own era probably qualifies (http://www.amazon.com/House-Cards-Robyn-Dawes/dp/0684830914).