The earliest identifiable proponent of what came to be known as New Thought was ~ ~ ≥ system that included the tenet that illness originated in the mind as a consequence of erroneous beliefs and that a mind open to God's wisdom could overcome any illness.
The earliest identifiable proponent of what came to be known as New Thought was Phineas Parkhurst Quimby (1802--66), an American philosopher, mesmerist, healer, and inventor. Quimby developed a belief system that included the tenet that illness originated in the mind as a consequence of erroneous beliefs and that a mind open to God's wisdom could overcome any illness.