Utilitarianism forms the basis of our current society, which is that we do whatever achieves the greatest happiness for the greatest number as they judge it and report. This runs into collision with an ethical argument first put forth in 1984 by Derek Parfit which became (deservedly) known as the repugnant conclusion.
The Stanford Encyclopedia of Philosophy explains the failure of utilitarianism in terms of population:
In Derek Parfit’s original formulation the Repugnant Conclusion is stated as follows: “For any possible population of at least ten billion people, all with a very high quality of life, there must be some much larger imaginable population whose existence, if other things are equal, would be better even though its members have lives that are barely worth living” (Parfit 1984). The Repugnant Conclusion highlights a problem in an area of ethics which has become known as population ethics. The last three decades have witnessed an increasing philosophical interest in questions such as “Is it possible to make the world a better place by creating additional happy people?” and “Is there a moral obligation to have children?”
We might view population as the metaphor, and the real question as, “which is better, excellence for a few or mediocrity for many?” In other words, are we aiming for quality or quantity, and if so, are we willing to sacrifice quantity for quality. The idea of utilitarianism is itself entirely quantitative, so we can see where this leads for the utilitarian idea
Parfit’s first and fatal error in attacking this question was to go full-metal Jeremy Bentham. In the proud tradition of scientific socialism, Bentham attempts to put a value metric on happiness. Parfit compounds this wrong further by partaking of the math-nerd version of Spirit Cooking. He uses the Benthamic concept of measuring happiness at the highest population number where H >= 0 for the individual person.
It gets to his choice of ethical systems. Parfit executes a moral decision-making model by using utilitarian ethics: do the greatest good for the greatest number and you will be less wrong. This misses the point entirely. No matter how sophisticated you make it, no matter how many silver-dollar words you describe it with, utilitarian ethics define morality on a basis of what makes the individual person “happy.” Therein lies the rub.
What makes an individual happy depends heavily on what sort individual you’re talking about. In world full of individuals like Trick Daddy, this reduces the epitome of morality to what fills a man’s stomach and stimulates his sex organs.
When I approach this problem, I’m thinking deontologically. As Omar put in on an episode of The Wire, “A man’s gotta have a code.” Rather than cribbing Jeremy Bentham, I would use Isaac Asimov’s methodology instead. Getting the toolbox out and tinkering with Psychohistory from The Foundation series, I came up with a different standard by which we can optimize human population.
Asimov worked as a chemist before his sci-fi blew up and he could earn a living writing articles for Playboy instead. A lynchpin concept in the study of physical chemistry involves a mathematical application of probability theory called statistical mechanics. Statistical mechanics estimates physical (or chemical) behaviors of a substance based upon a distribution of characteristics of individual molecules, atoms or particles contained in the substance. Asimov modified this intellectual framework to plant the theoretical axiom that a historian could start predicting the future history of a civilization based upon characteristics of that entity’s human population.
This leads me not to work towards an optimal population size at all. You don’t reproduce to fill up a cubicle farm. You also don’t cut people off of God’s psychopathic rugby football club just because you run out of jumpers. It’s not the size of the population in question that determines the good. It is the quality. Are these people intelligent? Are they industrious? Do they love their God and love their neighbor? Do they produce or do they mooch? Do they contribute or do they steal? Are they shiny, happy people? Who gives a rat’s rear-end unless they can honestly provide the correct answers to the first five questions?
So how many people do I order the good people to go forth and breed? He doesn’t. The correct question involves how good of a job can you do at g-loading them for war against powers and principalities and then how effectively and diligently are you working at optimizing that potential. Half of being good at mathematics is to know when to stop estimating based on knowledge you cannot yet possess. Sometimes Old-Fashioned Kentucky Windage gets you closer to hitting the target than obsessing over dialing that sight on your weapon with a nail.
So let’s talk reproductive strategy, not numbers. You’ve got two choices: r-strategy or K-strategy. So if you want to flood the zone, and hope that one or two them don’t wind up as casualties, you, like the rabbit or salmonella, choose r-strategy:
Those organisms described as r-strategists typically live in unstable, unpredictable environments. Here the ability to reproduce rapidly (exponentially) is important. Such organisms have high fecundity (glossary) and relatively little investment in any one progeny individual, they are typically weak and subject to predation and the vicissitudes of their environment. The “strategic intent” is to flood the habitat with progeny so that, regardless of predation or mortality, at least some of the progeny will survive to reproduce.
If you want your children to run with the big dogs and not once have to back down from life’s pissed-off grizzly… then breed fewer, breed better, breed K-strategy:
K-strategists, on the other hand occupy more stable environments. They are larger in size and have longer life expectancies. They are stronger or are better protected and generally are more energy efficient. They produce, during their life spans, fewer progeny, but place a greater investment in each. Their reproductive strategy is to grow slowly, live close to the carrying capacity of their habitat and produce a few progeny each with a high probability of survival.
Thus the repugnant conclusion ultimately pollutes the environment rather than solving the problem of how best to populate it. Earth’s K is not purely a function of how many? Ask “How abusive?”, “How needy?”, “How resilient?” and “How anti-fragile?” Essentially, reproduction should be informed more by the Deep Ecology of Arne Naess and not the shallow, mathematically sloppy socialism of Jeremy Bentham. That to me is a conclusion that is far less likely to make the man of intelligence and honor toss his cookies.