Crossing a road does not amount to consenting to being hit by a car, because the harm that may occur is not a biologically directed effect of the action itself. If a pedestrian is struck, the primary cause is another person’s recklessness or negligence, not something inherent to the act of walking across the street. The risk exists, but the injury is imposed by an external agent acting wrongly.
Sex is different in a morally relevant way. Unlike crossing a road, sex is an act that can foreseeably result in the creation of a new, inherently dependent human being, because that outcome flows from the biological function of the act itself—even when procreation is not the goal. When a vulnerable human is brought into existence as a foreseeable effect of a voluntary action, a minimal moral obligation follows: not to kill the human who has been placed in that dependent condition.
People are generally permitted to mitigate unwanted or harmful consequences of their actions. Medicine does this all the time. Treating lung cancer after years of smoking is morally permissible because the treatment does not involve harming or killing another person. But mitigation has limits. If addressing an unwanted outcome required killing an innocent third party, that “solution” would be morally disallowed.
Abortion falls on the wrong side of that line. It is classified as killing a human being and therefore cannot be justified as a permissible way to address the undesirable effects of consensual sex. The analogy to traffic accidents fails because pregnancy does not result from another person’s wrongdoing, nor is the unborn human an aggressor. The moral responsibility at issue is not consent to harm, but responsibility for how one responds to the foreseeable creation of a vulnerable human life.
Key Takeaways
Foreseeable responsibility: Voluntary actions carry responsibility for their foreseeable outcomes, even when those outcomes are unintended.
Key disanalogy: Harm in traffic accidents comes from external wrongdoing, while pregnancy arises from the biological nature of sex itself.
Limits of mitigation: Addressing unwanted consequences is permissible only when it does not require killing an innocent third party.
Minimal obligation: Creating a dependent human through consensual sex generates at least a duty not to kill that human.