The Enlightenment Context of Population Theories

In 1798, two seminal works on European population dynamics emerged from opposite ends of the continent, embodying the intellectual ferment of the Enlightenment era. Austrian political economist Joseph von Sonnenfels published Manual of the Domestic Administration of States, synthesizing traditional wisdom that viewed large and growing populations as essential for national prosperity. A leading figure of the Austrian Enlightenment, Sonnenfels argued that population growth should be the “first principle of political science,” vital for achieving material comfort and physical security. His reasoning reflected mercantilist thought: more citizens meant greater agricultural output, stronger defenses, and shared tax burdens.

Meanwhile, 32-year-old British scholar Thomas Malthus released An Essay on the Principle of Population, offering a radically pessimistic counterpoint. Challenging utopian thinkers like William Godwin, Malthus posited that population grows geometrically (1, 2, 4, 8…) while resources increase arithmetically (1, 2, 3, 4…). This imbalance, he warned, would inevitably lead to famine, disease, or “vice” (including contraception) as nature’s brutal checks.

Demographic Realities in Early Modern Europe

The late 18th century stood at a demographic crossroads. Sonnenfels’ Habsburg patrons, including Emperor Joseph II, actively pursued Peuplierungspolitik (population policies), believing “all state advantages derive from maximizing subjects.” Yet Malthusian crises persisted—France’s 1788-89 harvest failures exacerbated revolutionary tensions, while Ireland’s 1840s potato famine later validated his predictions.

European population patterns revealed stark regional contrasts:
– Northwest Europe: Lower fertility rates due to late marriage (average age 24-26) and high celibacy (10-25% of women).
– Eastern Europe: Earlier marriages and fewer economic barriers to family formation.
– Urban Centers: London’s population exploded from 200,000 (1600) to nearly 1 million (1800), sustained by migration.

Cultural and Social Impacts

### Marriage and Reproduction
In England, easy marriage laws (boys at 14, girls at 12) masked complex realities. Economic independence was expected before wedlock, leading to:
– Low Illegitimacy: Under 5% in most regions, though rising in cities (20% in Paris by 1789).
– Contraception: Coitus interruptus dominated despite religious condemnation. The infamous 1710 treatise Onania denounced it as “heinous sin,” while the Marquis de Sade offered… alternative suggestions in Philosophy in the Boudoir (1795).

### The Plague’s Retreat
By 1800, Europe’s “three horsemen”—famine, war, and plague—were diminishing. Key factors included:
– Quarantine Systems: Austria’s 1,900km Militärgrenze (military border) enforced 84-day quarantines.
– Medical Advances: Lady Mary Wortley Montagu popularized smallpox inoculation from Ottoman practices, later refined by Edward Jenner’s 1796 cowpox vaccine.

Legacy and Modern Parallels

Both Sonnenfels and Malthus were ultimately proven wrong—industrialization shattered Malthus’ resource ceilings, while nationalism replaced Sonnenfels’ population-as-power doctrine. Yet their debate echoes in modern discussions on sustainability, carrying capacity, and immigration policies.

The period’s demographic transitions also reshaped gender norms. While Mary Wollstonecraft’s Vindication of the Rights of Woman (1792) challenged patriarchal structures, most women remained economically dependent. Meanwhile, LGBTQ+ communities faced severe persecution—from Amsterdam’s 1730s anti-sodomy purges to London’s 1810 “White Swan Tavern” executions.

Conclusion: Between Growth and Limits

The 1648-1815 era witnessed Europe’s escape from Malthusian traps through colonization, agricultural innovation, and public health improvements. Yet its tensions—between optimism and catastrophe, individual rights and state control—remain strikingly relevant in an age of climate crises and demographic decline. As we grapple with these enduring questions, the voices of Sonnenfels and Malthus still whisper through the corridors of policy and philosophy.