Summarise:
From our discussion, it should be clear that the principle of procreative non-maleficence is not a zero-level threshold, meaning that the prospective child’s existence must merely be better than non-existence. The nonmaleficence threshold is higher. It applies the same
minimum standard that generally applies to the legal relationship between parents and their existing children to the legal relationship between parents and their prospective children. At the same time, the principle of procreative non-maleficence is not a maximizing principle but a sufficing principle, best conceptualized as establishing a threshold or minimum standard. Setting minimum standards
of conduct that parents must adhere to based on an evolving societal concept of harm is the way in which the law generally regulates the relationship between parents and their (existing) children. For instance, in most liberal democracies, parents are legally compelled to ensure that their children receive at least a basic education, but they are free to complement such basic education in
ways that they deem fit. Not receiving at least a basic education is generally perceived as harm to the child, and can lead to criminal—and perhaps even civil—liability of the parents. Likewise, prospective parents should be free to use genome editing technology to design their prospective children’s genetic makeup in any way that they deem fit—as long as they adhere to the minimum standard
of no harm to the prospective child.