The claim that a right to life depends on having a fully functioning brain does not hold up once its implications are examined. If all brain parts must be working, then many living people with neurological disorders, brain injuries, or developmental disabilities would lose their status as persons—an outcome almost no one accepts. Narrowing the rule to only “important” brain functions does not solve the problem, because it raises an unavoidable question: who decides which functions count as important, and on what non-arbitrary basis?
Appealing instead to current consciousness also fails. If being conscious right now were required for the right to life, then it would be morally permissible to kill a newborn in a temporary coma or a person under anesthesia. Since these conclusions are widely rejected, present consciousness cannot be the decisive criterion.
A more coherent approach distinguishes between an immediate ability to exercise consciousness and a deeper, higher-order capacity grounded in what a being is by nature. A person does not cease to be a person when that capacity is temporarily blocked or undeveloped. What matters is possessing, within one’s nature, the built-in capacity for consciousness—even if it cannot be exercised at the moment. On this understanding, embryos qualify as persons because they are biological humans of the kind that naturally develop and exercise consciousness over time, not because they currently have a fully functioning brain.
Key Takeaways
Requiring a fully functioning brain would exclude many disabled or injured humans, undermining equal human rights.
Standards based on “important” brain functions are arbitrary and lack a principled stopping point.
Making current consciousness the criterion would justify killing newborns or comatose patients, which is broadly rejected.
Grounding the right to life in human nature and intrinsic capacity consistently includes embryos, infants, and disabled persons alike.