Throughput
So here’s a thought experiment.
50 people wake up to discover that they have been kidnapped, abducted, or imprisoned. In any case, they cannot escape from their captors. Everyday these captors bring in just enough food for all 50 of them to survive on. All 50 prisoners understand that the amount of food provided will absolutely never increase, and that if any of them were to eat more than 1/50th of the food provided, than everyone else would have less to eat.
If you were one of these prisoners, would it be right of you to eat more than 1/50th of the food provided? Would it be unethical to eat more than your share and leave less for everyone else?
Suppose the years go by and this band of 50 survives. Being only human, sex becomes the primary pastime, and the captors graciously provide methods of birth control. Any child born in the prison would require just as much food as any other prisoner.
Knowing this, and that the amount of food provided will never increase, would it be right to forgo birth control, and to purposely have a child in the prison? Would it be unethical to reproduce?
If Jeremy Bentham was one of the prisoners, he’d have some answers. Bentham was a 19th-century philosopher, made particularly ill on half pints of shandy, and the progenitor of “felicific calculus”. As a utilitarian, Bentham would argue that actions are morally right or wrong based on their consequences, and that having a child is just as wrong as taking food from the mouths of other prisoners. If the prisoners made their own cute little society with their own adorable little system of justice, a utilitarian would argue that someone who had a child should be punished in the same way as someone who stole food from another.
If Immanuel Kant, the 18th-centruy German philosopher and rarely stable piss-ant was one of the prisoners, he’d have some different answers. Kant believed that the only measure of morality was the will as guided by reason. In order to be a moral principle, a rule must apply universally and must be consistent with reason. His theory of “The Categorical Imperative” demands that a rule of conduct should only be acted upon if can be applied universally and at the same time continue to be within reason. The act of eating more than anyone else fails as a moral principle because the concept of everyone eating more than everyone conflicts with reason. However, the act of having a child does not conflict with reason if it is universalized. In this way the two different actions, eating more and having a child, are not moral equivalents.
So let’s blow this up.
6,702,601,670+ people wake up and discover they’ve been born on a planet from which there is no means of escape. This planet has a limited carrying capacity, meaning sources (mineral deposits, aquifers, stocks of nutrients in soil) only produce natural resources at a certain rate, and sinks (the atmosphere, surface water bodies, landfills) only absorb waste at a certain rate. If we 6.7 billion prisoners exceed the throughput of of this planet, then our sources will run dry and our sinks will overflow.
So is it right take more than our fair share of natural resources and to produce more than our fair share of waste? Is it right to have kids faster than we’re dying? Is there any moral difference between the two?