The image of the human body and its pervasiveness in both thought and literature attest to Alexander Pope's declaration that the only true study of mankind is man himself. Nowhere is this sentiment more resolutely expressed than in the idea of the body politic. Ostensibly an organicist term for civil society, which enjoyed much currency during the seventeenth century, it nevertheless has a long and interesting genesis. Essentially concerned with organic metaphors for the social order of society, the term has endured into the parlance of the present day, enjoying something of a renaissance, due to the body becoming an object of fashion, and made visible thanks largely to the writing of Michel Foucault.
In classical literature, from Plato to Seneca, the analogy between body and commonwealth is idealized and polemical, rather than literal. Plato, in his Timaeus believed the cosmos to be of animate form, literally parallel to the human body. However, the State is not an animate body in a similar vein; moreover, it constitutes an artificial body, necessary for unity and society's evolution. Since Plato's anthropomorphic analogy is largely heuristic, he is more apt to compare the State with the individual man's life than with his body. In the Republic, the body plays an important role in Plato's political philosophy, with the three types of guardian, ruled by the tripart head, heart, and belly, each pursuing different goals. Aristotle's conception of the state was more mechanistic than Plato's, which explains Aristotle's use of body analogy in a more specifically corporeal way. This is especially true since the primary quality of Aristotle's association is the perfect integration of many working parts, and is much in evidence at the very beginning of The Politics.
Furthermore, the terms can be clarified by recourse to understanding the natural unities among the diversities formed within the human body. The kernel of this corporeal analogy makes an appearance in Shakespeare's Coriolanus, with Menenius Agrippa recounting the fable of the belly to pacify the plebeians. This story has its earliest outing in the second book of Livy's History of Rome, and has throughout its history followed closely along the lines taken by all the analogies of commonwealth and natural bodies. The belly, corpulent, idle, and seemingly lacking utility, takes in all the nourishment, while the other members, ceaselessly performing their functions, receive nothing for their labours. They rebel, and in some versions actually prevent the belly from receiving nourishment. Soon each member discovers that it is incapable of existence, since the belly not only takes in the food but distributes it accordingly among the other members. The belly therefore stands for some element of society that is perceived as surplus to requirement, the moral of this fable being that not only are tribunes, senators, and clergy indispensable, but also the amputation of any one part of the body politic has serious consequences for all the others. Livy, however, did not go to any great lengths to establish parallels between the body politic and organic analogous equivalents. Anatomical functions were described but not specifically given political equivalents.
The Christian Church has always had recourse to ideas of the body politic. Indeed, the Church regards itself as the embodiment of the mystical body of Christ. The doctrine of the corpus mysticum originated in Paul's Epistles. Exceeding Plato, Aristotle, and the Stoics in later influence, yet deriving from them, Paul expanded the analogy in novel ways, to propose theological, sacramental, and ecclesiastical doctrines, totally alien to pre-Christian authors. Paul's new comprehension of the analogy, in 1 Corinthians 12.8-31, was essentially a reworking of Seneca's, except an even greater emphasis was placed on the diversity of the body image. However, Paul's later epistles, composed when the danger of schism had somewhat receded, drew from the human body analogy the lesson which emphasized the total dependence of the members upon the head, which was Christ, at the expense of spiritual equality and co-operation between the members. Paul made the analogy more corporeal, by mapping the appetites and functions of the literal body onto the idealized, mystical body of Christ. The body politic, which can be likened to the actual body of Christ, or any other human body, is not merely identical to but actually is the body of Christ. In the mystery of the Eucharist lies the doctrine of the sacrament being the body of Christ. Within this framework is a fundamental union of the body politic with the specific, natural body, albeit an idealized one, of Christ. Thus, the Pauline analogy retains some of the flavour of classical rhetoric and idealization but adds diversity, physicality, and specificity with respect to the body of Christ.
The concepts of res publica and corpus mysticum, evoked by anthropomorphic analogies, gained currency in the Middle Ages as expressions of the medieval tension between the vision of cosmic unity and the evidence of diversity within the world. This polarity always provided the substance of the microcosmic body image, the analogy of which flourished in medieval thought. However, the unity of the corpus mysticum was confounded by the complexity and fragmentation of the medieval world. By the twelfth century, the Church had reaffirmed the actuality of the body and blood in the Eucharist against earlier heresies proposing purely mystical transubstantiation, and in the Church, due to its increasing social importance, the corpus mysticum became identified with the body of the faithful.
John of Salisbury in the twelfth century pioneered a full-scale anatomy of the anthropomorphic state. The result, Policraticus, detailed the community as a body, fully utilizing the lore surrounding the organic theory of the state, with the king as head, administrative officials and soldiers as the hands, and the peasants as the feet. Importantly, anatomical functions within the body politic are understood in precise terms. Nicholas of Cusa ultimately derived his De Concordiantia Catholica from Salisbury, although it is a conservative return to the organic and hierarchical vision of Church and State.
The expression of organic theory and of anthropomorphic analogy in Renaissance England, however, the so-called Elizabethan world picture, or the great chain of being, stretching from heaven down to earth, was above all a defence of the hierarchical status quo. Probably the ultimate expression of this sentiment is found in ceremony of the Royal Touch, which survived into the eighteenth century. However, Newtonian mechanics and atomistic visions of social order, which appealed to Enlightenment tendencies, replaced organic metaphors with those of a more mechanical kind — ‘the ship of state’ or ‘checks and balances’ to name but two.
— Mark Gosbee