Anti-natalism is the opinion that having children is unethical. It often overlaps with, but goes farther than, the childfree lifestyle.
Weak anti-natalism holds that having children is unethical in some circumstances or that the birth rate should be reduced, which are pretty mainstream beliefs. Strong anti-natalism holds that human reproduction is always wrong, a stance that implies support for (voluntary) human extinction.
There are three main arguments given for the position:
- Environmental: The human population causes harm to the environment, so don't make more humans.
- Misanthropic: Humans are assholes, and cause harm to each other, so don't make more humans.
- Philanthropic: Humans suffer, so don't make more humans.
- Weak philanthropic anti-natalists say that it is unethical to reproduce if your child would have a particularly bad quality of life. This can dovetail with eugenics or social Darwinism, since they generally believe that "poor people" or "people with bad genes" should not reproduce, but that others may do so ethically.
- Strong philanthropic anti-natalists go even further and argue that the unborn cannot consent to existence at all, that there is an asymmetry between suffering and happiness, that it's unfair to gamble with even a small possibility of exposing your child to severe forms of suffering, etc. This position generally implies that it would be a good thing for humanity, or maybe even all sentient life, to go extinct.
Pro-natalists respond to philanthropic anti-natalism by pointing out that anti-natalists are just depressed, and that most people enjoy their lives overall and don't hate their parents for giving birth to them. They also point out weaknesses in the philosophical underpinnings of anti-natalism. Furthermore, natalists like Bryan Caplan argue that population growth has a positive effect on the world, in direct contrast to misanthropic and environmental anti-natalist views.
Anti-natalism vs. Childfree
Anti-natalists are opposed to reproduction in general, including when other people do it. They often refer to people who have children using the derogatory term "breeder".
Childfree people usually don't really care about whether other people have kids, they just personally choose not to do so.
Another example of how moralist anti-natalism and selfish childfree-ism differ is their stance on adoption. Anti-natalists often support adoption, since it improves an already-born child's life without increasing the human population. Childfreers generally flinch at the idea because they'd rather spend their money on expensive vacations or video game collections instead of raising a random orphan.