擬制血親與宗族
馮爾康
歷史上的宗族，成員間具有男系血緣關係，這是宗族組成的要素和不可動搖的原則，但是在社會實踐中，人們間又有擬制血親及類似擬制血親的社會關係，與宗族糾纏在一起，並且擺脫不開。這種歷史現象，涉及到個人、家庭與宗族的關係，宗族與政治的關係，社會人際關係、社會風俗和社會倫理，似有必要對其作一番清理。
本文分三個部分論述這一課題，即：一、歷史上擬制血親的類型，二、宗族與擬制血親的關係，三、擬制血親與宗族伴存的原因及影響。
本文概括歷史上的擬制血親和類似擬制血親的現象為八種類型，即皇家的賜姓、同姓不宗者間的聯宗、收養異姓為子、認乾爹娘、結拜金蘭、招婿承嗣和外甥繼嗣、主佃東伙的少長關係、奴從主姓。古人在理論上提出生功（親生父母的誕育之功）與養功（養父母的養育之功）孰重的問題，探討異姓為後的某種合理性。
擬制血親與宗族的血緣原則相悖，但是又以宗親關係為模式向宗族靠攏；宗族面對擬制血親的挑戰，以反對異姓亂宗和講究同姓不宗為理論，以宗族有關的規範為武器，在行動上予以打擊，同時被迫承認某些事實，如結義、拜乾親以及皇家主動作的賜姓。因此雙方形成排斥與吸納的矛盾統一關係。
擬制血親調節家庭與宗族不協調的方面，適應古代家庭建設和發展的需要；她被人們用作社會關係和社交手段，在社會生活中發揮作用，對移民在新區的立足尤有價值；她在一定意義上迎合古代政治需要，維護某些王朝政權和某些家族勢力。
關鍵詞：宗族 擬制血親 聯宗 生功 養功
Feng Erkang
Department of History, University of Nankai at Tianjin
Historically, in the paternal clan system, there has remained one immutable condition: relations are determined by the male blood lines. However, practically speaking, society has also maintained a system of fictitious blood relations. This kind of relationship, often in conflict with the system of paternal clans, has never been completely shed. Because this phenomenon is so intricately related to the conception of family, of society and politics, of the collective and individual, of customs and ethics, it is, therefore, a topic worthy of discussion.
This paper is divided into three parts: 1) the various forms of fictitious blood relation, 2) the relation between fictitious and paternal blood ties, 3) the coexistence of these two institution.
I have divided fictitious blood relations into eight distinct categories: 1) the imperial bestowal of surname, 2) the joining of peoples of different ancestry with the same surname, 3) the fostering of a son bearing a different name, 4) the establishment of nominal parental relations, 5) the establishment of nominal fraternal/ sororate relations, 6) the bestowal of inheritance and/or succession rights upon the son-in-law, or nephew, 7) the establishment of patriarchal relations between landlords and tenants, or between masters and servants, 8) the acquiring of surname through the institution of slavery.
Fictitious blood relations were contradictory to the paternal clan system. Yet, paradoxically, they relied upon this system as a guarantee of their existence. Exponents of the paternal clan system attacked fictitious blood ties as a confusion of name, clan, and ancestral ties. Simultaneously, they were compelled to accept various aspects of this institution, including nominal fraternal/sororate relations, nominal kinship, and imperial bestowal of surname. These two systems of relationships were mutually exclusive, yet relied upon one another for their continuance.
The system of fictitious blood relationships was a means of adjustment within the larger context of the paternal clan system, well-suited to the establishment and development of families in ancient China. It served its function by facilitating social relations and social intercourse, particularly in the instance of emigrant life. Politically, it was an excellent means of consolidating power both in government and among individual families.
Keywords: Clan, Fictitious blood relations, United clans with different lineage, Natural parents' contribution