고려시기 계후(繼後)의 의미와 조선전기 입후법(立後法) 제정에 따른 개념 변화 -양자(養子)와 후사(後嗣)를 중심으로-

This study analyzes the concept and evolving roles of adopted children(養子) during the Goryeo and Joseon periods. According to actual cases from the Goryeo era, adoption was primarily driven by practical purposes such as inheritance of official duties and property, rather than the Joseon-era practice of succession for ancestral rites and family lineage. In Goryeo, succession(繼後) meant becoming the representative of the household(戶), inheriting official roles, including government posts. Because ancestral rites were conducted rotationally(輪回奉祀), it did not imply succession rights to perform rituals as it did in the Joseon era. The successor represented the next generation of the household and included successors to official duties determined by status or established practice. During the Goryeo period, candidates for succession were blood relatives. Not only patrilineal relatives but also affinal relatives such as sons-in-law and female descendants were eligible, including children born from concubines(庶孽). Additionally, a child raised from infancy(收養子) could inherit succession rights after blood relatives. Thus, in the Goryeo period, adopted children were differentiated into two categories：those raised from infancy and adults adopted later(養子). In contrast, during the Joseon period, emphasis was placed on the Confucian ancestral rites system, grounded in patrilineal lineage. Joseon enacted the law of establishing successors(立後法), strictly limiting succession to patrilineal descendants. Consequently, along with the earlier classifications of adopted children based on three generations (suyangja and siyangja), successors defined by the iphubeop emerged. Although iphubeop was introduced, its practical implementation remained inconsistent until the 16th century, closely resembling Goryeo practices. However, in the late Joseon period, the law became widely established, explicitly restricting lineage succession and ancestral rites to patrilineal descendants, clearly defining the roles and privileges associated with succession. Thus, the Goryeo-era concept of adoption was further subdivided into terms such as suyangja, siyangja, yangja, and iphuja during the Joseon era. These transformations highlight changing perceptions of family succession practices between the two periods.