The Father of Population Control

To the prophet Jeremiah's timeless injunction, "Increase in number!" modern culture adds the caveat: "but no more than is sustainable."

The last half-century has witnessed the emergence of a new class of ethical imperatives about the impact of human existence. Whether motivated by worries about healthcare, overpopulation, overconsumption, or ecological disaster, these have come to take precedence over age-old injunctions passed down from the Judeo-Christian tradition. So entrenched are concerns about our collective human "footprint" in the contemporary moral scheme, that a New York Times article last year likened adultery to the "depravity" of "driving when I could take a train." These new ethical preoccupations reflect a deep, arguably metaphysical, transformation in how we think about human existence.

This should come as no surprise: all ethics assume a metaphysics. Aristotle's ethics of virtue took root in the notion that everything in nature has a purpose, while the Stoics, for whom God was the animating principle of nature, called metaphysics the soul of philosophy, ethics its flesh. For much of Western history, the idea that creatures participate in a universal and hierarchical tapestry of existence -- the Great Chain of Being -- was the metaphysical underpinning of the Christian ethical vision. Existence as such was taken to be a "perfection."

In the 11th century AD, St. Anselm of Canterbury argued that one could logically deduce God's existence from the traditional definition of God as the most perfect Being. The idea that existence is a perfection played a crucial role in this "ontological argument." It is beautifully simple:

• God is "that than which no greater can be thought."

• I have an idea of "that than which no greater can be thought."

• "that than which no greater can be thought" exists in the mind.

• It is better to exist within the mind and without, than to exist only in the mind.

• "That than which no greater can be thought" exists within the mind and without.

• Conclusion: God exists.

Anselm's proof has a long history and is thought by many to be unconvincing today. One famous objection came from St. Thomas Aquinas, who argued that Anselm surreptitiously conflates two meanings of the word "existence," committing what philosophers call a fallacy of equivocation. This put a long-standing moratorium on such purely rational proofs. (Aquinas's own arguments for God's existence began with observations, not definitions). Nevertheless, Aquinas elsewhere put the idea that existence is a perfection on a rigorous scholastic foundation -- preserving Anselm's metaphysics, if not his syllogism.

Descartes shook the dust off Anselm's argument as late as the 17th century. If God is the most perfect being, he reasoned, and if existence is a perfection, then God must exist. Thus, the notion that existence is a perfection went largely unassailed for over half a millennium, until Immanuel Kant argued that existence is no metaphysical property at all. The very attempt to deduce God's existence through "pure reason," Kant argued, was misguided.

As undergraduates, my peers and I were asked by our Medieval Philosophy professor to come up with an objection to Anselm's proof. "'I don't like it,'" he used to say, "is not an argument!" Despite the scoffs and eye rolling, nobody hit on either Aquinas's or Kant's objection. Rejected instead was the whole notion that one form of existence could be more "perfect" than any another. This idea seemed metaphysically, even morally, repugnant.

This is an eminently modern reaction. To paraphrase Bertrand Russell, it is hard to find a fallacy in the ontological proof, but it somehow feels fallacious. (Lord Russell would not have fared well in our Medieval Philosophy class). The reason is that the entire metaphysical worldview underpinning Anselm's argument has been lost. At best, we find echoes of it in religious beliefs and morality; at worst, history books recall a quaint vision of a world in which angels pushed the celestial bodies along their eternal paths.

Moses Mendelssohn called Kant the "all destroyer" for his rejection of the ontological argument and its underlying metaphysics. Our contemporary metaphysical and ethical worldview, however, owes less to Kant than to his Swiss predecessor, Jean-Jacques Rousseau.

In 1754, almost thirty years before Kant's Critique of Pure Reason, Rousseau sought to determine the origins of inequality among men. To do so he postulated an ideal state of nature, which was characterized by harmony with the natural world and with one's fellows, rather than by war, antagonism, and chaos -- as were the fictions of his Hobbesian predecessors.

Man, thought Rousseau, did not possess a perfection but rather a capacity he called perfectability, his term for the ability to adapt and change as a species. This capacity, which distinguished man from beast, was also man's downfall. How so? In Rousseau's words: "to the extent that the human race expanded itself, man's troubles multiplied."

Population growth meant the expansion of social intercourse and an array of new "artificial" desires and demands. To satisfy them, man had to cultivate land, rank his fellows according to their labor capacities, establish property, the division of labor, and trade. This led, in turn, to greed, selfishness, and what Rousseau called self-love (amour propre). Thus the introduction of civilization led to man's Fall, his ultimate corruption.

Often overlooked in this scenario is that the expansion of man's collective existence is what made civilization a necessary evil in the first place. Rousseau's new Eden shares at least one feature with its Biblical predecessor: it had a small human population.

This myth of origins brings into relief a very contemporary problem, namely how to exist in a cultivated and populous state while trying to preserve as much as possible the natural harmony that our cultivation and our population disturbed. An operative sentiment in this scheme is guilt -- in this case about our collective cultivated existence. Ironically, Rousseau, the philosopher of the "sentiment of existence," bequeathed to us an existential guilt.

In the medieval picture, man was created in the image of God, but he was also sinful; existence was a perfection, but human nature was corrupt. Guilt and the expulsion from Eden came from our choosing evil. In the modern picture, this scheme is inverted: man's very form of existence is the root of corruption. We are banished from Arcadia, not for our actions, but for having existed too much.

Thus the ethical imperative becomes a matter of limiting the impact of human existence so as restore natural harmony. This idea is taken to its extreme in many contemporary ecological ethics where neo-Malthusian worries about resource depletion lead with alarmingly little friction to talk of population control. This ethical framework, like its medieval predecessor, assumes its own metaphysics: no longer a "perfection," human existence is understood as a potential blight on a state of natural equilibrium -- an imperfection, whose "footprint" portends calamity.

The wish to conserve is laudable, so too the wish to temper the inexhaustible desire to consume. About these matters Rousseau was prescient. But he was equally prescient about the dangers of impinging on human freedom and the urgency -- and possibility -- of moral betterment, perfectibility. In this there are echoes of a more ancient idea as well as a reminder. In moving man from the center of our cosmos to the center of our moral scheme, we have also robbed him of something metaphysically precious: a perfection.