Although filial conduct changes with the times, "spiritually, the affections that connect the two generations never disappear" writes Yeh, who explains that spiritually filial piety is based on the principle of "giving back" and that mutual affections are of paramount importance. Filial piety is something akin to the Confucian concept of "a loving father and devoted son."
但實質的孝行雖然隨時代遞嬗，「孝道的精神層面，也就是情感的連結，卻是千古無法抹滅的，」葉光輝提醒，從精神上而言，孝道是建立在「報」的原則上，講究的是相對性的情感基礎，正如儒家的父慈子孝，是一種「相對性的孝道」。