Ethical Precision in Nanoscale Brain Interfacing

Recent advances in nanotechnological brain interfacing are transforming precision from a technical achievement into a new form of intimate access to neural and mental life. Nanoscale sensors and stimulators approach synaptic resolution while reducing anatomical invasiveness, yet this same refinement increases moral invasiveness by enabling inferences about states, dispositions, and traits that individuals may not intend to disclose. To clarify the ethical implications of this shift, the recovery-discovery framework is applied, which conceptualizes neurotechnological uses along two continuous dimensions: restoring prior function (recovery) and generating new knowledge or capacities (discovery). At the nanoscale, these orientations become probabilistically entangled: recovery requires unprecedented characterization of neural pathways, while discovery introduces uncertainty and potential perturbation, creating new or unforeseen needs for recovery. This entanglement undermines device-centric and episodic models of oversight, requiring ethics to become continuous, operation-sensitive, and context-aware. Drawing on insights from science and technology studies and safety cultures such as aviation, the article proposes an architecture of ethical precision, including purpose-bound operation, capability pre-registration, epistemic firewalls, intimacy indices, reversibility budgets, and ethics telemetry-to govern intimate neural access with proportionality and accountability. Precision brain interfacing will advance not only through technical refinement but through the precision of the ethical practices.