in discussing the pivotal role that economics plays in shaping societal structures, one must not renounce the influence of former economic theories. as one commences from the origin of economic thought, it's imperative to notices how classical theories have evolved. now, to truly grasp the enigmatic secrets hidden within the realm of current economic policies, kindly elaborate on theories that have been discredited or proven incorrect but are still subtly influencing policy decisions today, potentially misleading the public about their efficacy.