The customary division of national laws of citizenship intonthe “principles” of jus soli (place of birth) or jus sanguinisn(line of descent) denotes the objective criteria most oftennused to determine one’s citizenship. But the conceptions ofnpolitical membership that have vied for supremacy in Anglo-nAmerican law implicate a different, more fundamental dichotomy—onenbetween the rival principles of ascription andnconsent. These principles reflect quite distinct understandingsnof the origins, nature, and obligations of political communities,nand each promotes certain values that Anglo-American legislatorsnand judges have embraced at different times and oftennsimultaneously. At least since the 18th century, Anglo-Americannlaw has embodied compromise doctrines that combinencertain features drawn from each conception in the hope ofnproducing pragmatic satisfaction, if not theoretical coherence.nAs we shall see, however, the two principles are not so easilynblended.nIn its purest form, the principle of ascription holds thatnone’s political membership is entirely and irrevocably determinednby some objective circumstance—in this case, birthnwithin a particular sovereign’s allegiance or jurisdiction. Accordingnto this conception, human preferences do not affectnpolitical membership; only the natural, immutable circumstancesnof one’s birth are considered relevant. The principle ofnconsent advances radically different premises. It holds thatnpolitical membership can result only from free individualnchoices. In the consensualist view, the circumstances of one’snorigins may of course influence one’s preferences for politicalnaffiliation, but they are not determinative.nPeter H. Schuck is Simeon E. Baldwin Professor of Law atnYale Law School, and Rogers M. Smith is a professor of politicalnscience at Yale University. This article is based on theirnJ 986 book, Citizenship Without Consent: Illegal Aliens innthe American Polity (Yale University Press).nConsensual Citizenshipnby Peter H. Schuck and Rogers M. SmithnEnglish law assumed from antiquity that all persons bornnwithin the dominions of the crown, whether of English ornalien parents, were English subjects. Yet neither members ofnthe royal family nor the children of English subjects couldnlose any rights due to birth outside the king’s domain. Nontheory of membership that could account for these diversenprecedents was formally elaborated until 1608, when Sir EdwardnCoke in the landmark Calvin’s Case elaborated “the-firstncomprehensive theory of English subjectship.” His theorynbased that status firmly on the ascriptive principle. Through itnCoke established once and for all the common membership ofnScots and Englishmen in one united community of allegiance,nregardless of any contrary indications in any past or futurenman-made law. To reach this result. Coke appealed to naturalnlaw, thereby giving birthright political membership thenstrongest possible sanction.nNatural law dictated, he held, that one’s political identity isnautomatically assigned by the circumstances of one’s birth.nCoke understood political identity as being at root a questionnof one’s allegiance as a subject to some sovereign. At birth, everynperson acquired such an allegiance. The subject owedncomplete obedience and service; the sovereign owed physicalnprotection and just governance. Being imposed by the eternalnlaw of nature, which was prior to all man-made law, both obligationsnwere perpetual and immutable. Expatriation and denationalization—terminationnof the allegiance between a natural-bornnsubject and his sovereign by either the individual ornthe government—were considered contrary to natural law andntherefore impossible for either party.nThe ascriptive view of Coke, although deployed for particularnpolitical purposes, has more universal attractions. It capturesna widely shared moral intuition: many persons feel indebtednto those who have nurtured them, including thenbroader political community into which they were born, despitenthe fact that they did not initially choose to receive thatnnn)ULY 1992/21n