Phineas Quimby was an American mental healer whose ideas greatly influenced the New Thought movement, a religious-metaphysical healing group. He originally studied mesmerism and became a practitioner of hypnosis. He claimed that he could heal by mere suggestion. Quimby believed that illness originated in the mind and was created by erroneous beliefs. He taught that when a person opened their mind to God’s wisdom, they could conquer any sickness.

One of his patients and disciples was Mary Baker Eddy, the founder of Christian Science. When Eddy moved into her own work she denied Quimby had made any contribution to the theory of Christian Science.