Some psychologists claim that, in theory, the best way to understand another person would be through deep empathy, whereby one would gain a direct and complete grasp of that person' s motivations  But suppose they are right; then there would be no way at all to achieve understanding, since it is psychologically impossible to gain a direct and complete grasp of another person' s motivations
But obviously one can understand other people; thus these psychologists are wrong
confuses a theoretically best way of accomplishing something with the only way of accomplishing it