Often used to express disapproval in ethical debates about science, like cloning. Cloning animals is against nature, it raises many ethical questions.
Pro Tip 2/3
Emotional Charge
Can carry a strong emotional weight, implying that something is not just unusual, but wrong. They said building a dam in the wildlife reserve was against nature.
Pro Tip 3/3
Environmental Concern
Common in discussions about human impact on the environment or ecosystems. Pouring waste into the ocean is an act that's against nature.