Freudian slips, technically called parapraxes, are errors in speech, memory, and action that appear random but reveal unconscious thoughts and wishes. You call your new partner by your ex’s name, forget an appointment you claimed you wanted to attend, misplace an object belonging to someone you resent. These are not meaningless accidents. They are motivated by unconscious content that momentarily overcomes conscious intention. The mistake reveals what you really think or feel beneath your conscious presentation. The fundamental insight is that there are no accidents in mental life. Every slip, every forgetting, every bungled action serves a psychological purpose. The...