No imposition is too great for the credulity of men

People don’t limit themselves to merely believing that absurd but harmless quackeries are actually effective medicine: the human capacity for wishful thinking is so potent that countless people throughout history have sworn by dangerous snake oils even as they were being slowly destroyed by them. “That’s how you know it’s working” is an easy rationalization.

Consider this the next the time you hear (or say) “it worked for me.” People once talked that way about their fashionable lobotomies!

Nothing more strikingly betrays the credulity of people than medicine. Quackery is a thing universal and universally successful. In this case, it becomes literally true that no imposition is too great for the credulity of men.

Henry David Thoreau

Here are some colourful historical and current examples of dangerous-but-popular treatments, just updated with that irresistibly apt Thoreau quote, and couple new examples: black salve and vagina steaming.