Placebo effect

The placebo effect is the body's response to a treatment. It can involve an actual physiological response.

Sourced

• No one doubts—certainly not I—that the mind exercises a powerful influence over the body. From the beginning of time, the sorcerer, the interpreter of dreams, the fortune-teller, the charlatan, the quack, the wild medicine-man, the educated physician, the mesmerist, and the hypnotist have made use of the client's imagination to help them in their work. They have all recognized the potency and availability of that force. Physicians cure many patients with a bread pill; they know that where the disease is only a fancy, the patient's confidence in the doctor will make the bread pill effective.
  • Mark Twain, Christian Science (1907), Chapter IV.

• Genuine and remarkable cures have been achieved through contact with the relics of a saint. Is it not likely that any other bones would have done as well if the substitution had been concealed from the patient? When I was a boy a farmer's wife who lived five miles from our village had great fame as a faith-doctor—that was what she called herself. Sufferers came to her from all around, and she laid her hand upon them and said, "Have faith—it is all that is necessary," and they went away well of their ailments. She was not a religious woman, and pretended to no occult powers. She said that the patient's faith in her did the work. Several times I saw her make immediate cures of severe toothaches. My mother was the patient. In Austria there is a peasant who drives a great trade in this sort of industry, and has both the high and the low for patients. He gets into prison every now and then for practising without a diploma, but his business is as brisk as ever when he gets out, for his work is unquestionably successful and keeps his reputation high. In Bavaria there is a man who performed so many great cures that he had to retire from his profession of stage-carpentering in order to meet the demand of his constantly increasing body of customers. He goes on from year to year doing his miracles, and has become very rich. He pretends to no religious helps, no supernatural aids, but thinks there is something in his make-up which inspires the confidence of his patients, and that it is this confidence which does the work, and not some mysterious power issuing from himself.
  • Mark Twain, Christian Science (1907), Chapter IV.