Schey speculates that Einstein's antipathy to quantum theory may have been determined in part by intrapsychic conflict. This conjecture is based on a parapraxis

contained in a letter Einstein wrote to Schrödinger on April 16, 1926. In the letter he quarreled with an equation he mistakenly attributed to Schrödinger and offered as his own one that had actually been proposed by Schrödinger. Einstein spontaneously recognized his error and acknowledged it in a letter written six days later. He objected strenuously to quantum theory because of its inherent probabilistic description of physical phenomena. Schey suggests that unconscious envy of Schrödinger's achievement played a role.