The asymmetry is the view in population ethics that, while we ought to avoid creating additional bad lives, there is no requirement to create additional good ones. The question is how to embed this intuitively compelling view in a more complete normative theory, and in particular one that treats uncertainty in a plausible way. While arguing against existing approaches, I present new and general principles for thinking about welfarist choice under uncertainty. Together, these reduce arbitrary choices to uncertainty-free ones, regardless of how the latter should be made. I illustrate these principles by developing two theories of the asymmetry, reflecting different views about the non-identity problem. In doing so, I clarify some other major choice-points, presenting new arguments that creating additional good lives can justify (but not require) doing harm. Finally, I consider what the developed theories have to say about the importance of extinction risk and the long-run future.

中文翻译：

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不对称性、不确定性和长期性

这种不对称是人口伦理学的观点，即虽然我们应该避免创造更多的糟糕生活，但没有必要创造更多的美好生活。问题是如何将这种直观上令人信服的观点嵌入到更完整的规范理论中，特别是以合理的方式处理不确定性的理论。在反对现有方法的同时，我提出了思考不确定性下福利主义选择的新的一般原则。总之，这些将任意选择减少为无不确定性的选择，无论后者应该如何做出。我通过发展两种不对称理论来说明这些原理，反映了对非同一性问题的不同观点。在此过程中，我澄清了其他一些主要选择点，提出了新的论点，即创造更多的美好生活可以证明（但不要求）伤害是合理的。最后，我考虑了现有理论对灭绝风险和长期未来的重要性的看法。