The Measure of Multitude: Population in Medieval Thought (review)

This pioneering book explores a multitude of texts written by Latin Christians between 1100 and 1340, carefully sifting out changes in understandings of human population phenomena. Peter Biller, a senior lecturer at York University in England, explains in his introduction how he stumbled onto his subject by "an accidental union of teaching and reading" (p. 1) that led him to expect that the changing demography of Latin Christendom between 1100 and 1340, as reconstructed by contemporary historians, ought to have induced Latin Christians to think "about the things we bundle together under the heading 'demography': the population of different countries, the sex ratio, life-span, and such-like" (p. 5). And sure enough, years of diligent search turned up a long series of relevant passages whose nuances of meaning he explores with painstaking precision in the following chapters.

To quote Biller once more:

The different types of texts which can be used to explore these questions supply the structure of this book. The Church's theological and canon-legal texts concerning marriage and population occupy Part 1 (Chapters 2-8), while texts concerning geography, the Holy Land, conversion, and population beyond Latin Christendom are examined in Part 2 (Chapter 9). Part 3 looks at texts translated from Greek and Arabic, with Chapter 10 focusing on the natural-philosophical and medical texts, and Chapters 11-13 on one work of moral philosophy, the Politics.. . . The final chapter . . . takes one city around 1300, Florence, and asks "How was demographic thought represented here in one place?" This chapter, in turn, has its coda with which the chapter and book end: demographic thought in the work of one former Florentine, Dante. (pp. 8-9)

By translating and commenting on phrases from a profusion of relevant texts, Biller reveals the liveliness of inquiry into human numbers, sexual reproduction, and related questions that prevailed in Paris and other centers of learning after 1100.

Intersecting stimuli were at work. Here, for example, is what Biller says about the deliberate limitation of births:

The pressure of population on resources, the behavior of married people, and the increasing presence and variety of relevant medicine were all exercising pressure, stimulating thought and making it more complex, while it was being coaxed into a generalizing mode both by the growth of pastoral "sociography'" . . . and increasing familiarity with book 7 of Aristotle's Politics, which we will discuss in Chapter 13 below. Birth control is anachronistic certainly. But the gap between the modern phrase and medieval thought was narrowing markedly around 1300. (pp. 211-12)

Expanding geographic knowledge also had its effect. In particular, the Mongol empire of the thirteenth to fourteenth centuries introduced China and the vast Asian steppelands to Latin Christians, and "trustworthy merchants" dealing in exports from the African coast of the Indian Ocean proved the existence of human habitation south of the equator as well. As a result, a Dominican missionary named Raymond Stephani could write in 1332 that Latin Christians constituted "not even a twentieth part of the inhabited world" (p. 249).

Yet reading these chapters is often heavy going. The innumerable excerpts from many different writers, each painstakingly paraphrased and compared with others, quickly become confusing. And in the end Biller declares his own uncertainty as to whether there was "rough and primitive 'demographic thought'" to be found in the texts he examined (p. 418). For even if William of Auvergne, bishop of Paris 1228-49, "addressed fertility in western Christian marriages, avoidance of offspring, sterility among prostitutes, the relation of a polygamous system to the sex-ratio, and the comparative population densities of a polygamous Islamic and monogamous Christian country: all in one treatise," he was writing about marriage, whereas "modern demography in its impersonal reduction of humans to quantity and its odd mix of bits of biology, geography and sociology" is "rather...