Vox
June 30, 2026
The Guilt of Justified Killing: Understanding Moral Residue
TL;DR
The feeling of guilt after killing bugs—even when justified—is called moral residue, a phenomenon that occurs when you do something you believe is right but also morally wrong.
Key Takeaways
- 1Moral residue is the guilt felt when performing an action that is simultaneously right and wrong, such as killing invasive species for ecological good
- 2Three ethical frameworks can justify killing lantern flies: consequentialism (judging by outcomes), deontology (judging by motivations), and virtue ethics (judging by character)
- 3Killing spotted lantern flies slows their spread rather than eliminating them, giving unprepared regions like California time to develop defenses
- 4Justified actions can still feel morally wrong, and acknowledging that discomfort is a valid ethical response
Notable Quotes
“It happens when you do something you think is right but also wrong, like killing living creatures for the greater good.”
— Narrator
“I have decided I will be stomping lantern flies this summer. Just not gleefully.”
— Narrator
Chapters
1. The Invasive Lantern Fly Problem
Every summer on the East Coast, people are encouraged to kill invasive spotted lantern flies to protect crops, especially grapes. The goal isn't total eradication but slowing the spread to give unprepared regions time to prepare.
2. Three Ethical Frameworks for Justification
Consequentialism judges decisions by their outcomes, deontology considers motivations, and virtue ethics examines character. All three frameworks can provide valid reasons for killing lantern flies.
3. Moral Residue: The Discomfort of Justified Actions
Despite logical justification, the act of killing living creatures for the greater good produces a persistent feeling of guilt called moral residue—the discomfort of doing something that feels both right and wrong simultaneously.
4. A Personal Resolution
The speaker decides to participate in killing lantern flies this summer but will do so without joy or satisfaction, acknowledging the moral weight of the action.
Glossary
- Moral residue
- The persistent guilt or discomfort felt after performing an action that is simultaneously justified and morally troubling
- Consequentialism
- An ethical framework that judges the rightness of an action based on its outcomes or consequences
- Deontology
- An ethical framework that judges actions based on duties, rules, and the motivations behind the action rather than outcomes
- Virtue ethics
- An ethical framework that focuses on developing good character traits and virtues rather than rules or consequences
- Spotted lantern fly
- An invasive insect species that damages crops, particularly grapevines, and is native to Asia