According to Zhu Xi, individuals are transformed into moral beings through the cultivation of their character, and the increase of moral individuals therefore leads to the generation of a moral society. While acknowledging that moral success through such cultivation produces moral heroes, Dasan Jeong Yak-yong argued that inner cultivation alone could not produce moral individuals and a moral society because in reality humans have a myriad of conflicting desires and fluctuating volitions. Without confining morality to the purification of inner mind, Dasan considered both inner reflection and external practice grounded on free will to be necessary. Through both, he believed, individuals attain a personal sense of responsibility and preside over the entire process of morality. Although in reality there are personal differences, people can partake proactively in the construction of a moral society. In this regard, Dasan is credited with shifting the focus of Confucianism from the sage and his inner reflection to common people and practice.