Our sages have said: “Do not judge your fellow until you have stood in his place” (Ethics of the Fathers 2:4). Since the only person in whose place you can truly stand is yourself, this means that you are qualified to judge only yourself. Regarding yourself, you must condemn your moral and spiritual failings and be critical of your every achievement. Regarding your fellow, however, you must employ a double standard: your love and esteem toward him should be amplified by every positive quality you see in him, and should not to be affected in the least by any seemingly negative things you might observe.
— Rabbi Schneur Zalman of Liadi