By Shadi Nasseri
Human beings are vulnerable in ways that law has long recognized. Our bodies can be harmed, our liberty constrained, our property taken. Yet the deepest vulnerability of the human condition may lie elsewhere, in the human mind itself. Thoughts can be influenced, shaped, persuaded, and manipulated. To be sure, such influence is not entirely new. Pharmacological interventions, from psychoactive medications to chemical agents capable of altering mood, perception, and cognition, have long demonstrated that the mind is not wholly insulated from external interference. Yet for centuries, the mind has largely remained beyond the direct reach of technological intervention. That assumption is rapidly changing. Emerging technologies, particularly neurotechnologies and artificial intelligence systems capable of analyzing neural signals, are beginning to challenge the long-standing boundary between the internal life of the mind and the external world regulated by law.
This challenge formed the central theme of a recent lecture by Professor Christoph Bublitz titled “Defending the Absolute Nature of Freedom of Thought,” accompanied by commentary from Professor Hengameh Saberi. Their discussion examined one of the most underdeveloped yet foundational rights in international human rights law: the right to freedom of thought.
Freedom of thought has deep intellectual roots in Enlightenment philosophy. Thinkers such as Immanuel Kant framed intellectual autonomy as the defining mark of human maturity. To “think for oneself,” in this tradition, meant exercising reason independently of external authority, pursuing truth through rational inquiry rather than obedience to dogma. Enlightenment notions of freedom of thought were therefore closely associated with the flourishing of science, intellectual independence, and the rejection of authoritarian control over belief.
Yet international human rights law employs the concept in a more precise sense. In legal doctrine, freedom of thought refers not primarily to the public expression of ideas, but to the internal processes of thinking itself. It protects what has historically been described as the forum internum—the inner sphere of belief, conscience, reasoning, and reflection.
This distinction is reflected in Article 18 of the Universal Declaration of Human Rights (UDHR) and the International Covenant on Civil and Political Rights (ICCPR). These instruments protect freedom of thought, conscience, and religion without qualification in their internal dimension, while allowing certain limitations on their outward manifestations. In other words, the law distinguishes between what occurs within the mind and what is expressed externally.
Professor Bublitz’s lecture traced the drafting history of Article 18 to demonstrate that freedom of thought was conceived as a particularly strong right from its inception. During the drafting of the UDHR in the late 1940s, the Lebanese philosopher-diplomat Charles Malik played a crucial role in advocating for the explicit inclusion of freedom of thought. Malik argued that human beings are not merely material creatures requiring economic and social protections, but also intellectual and spiritual beings whose inner freedom demands legal recognition.
The context of the post-war world made this concern particularly acute. The rise of mass propaganda, ideological manipulation, and authoritarian control had demonstrated how profoundly the state could shape belief and perception. Malik warned that the modern state increasingly exercised power through psychological, economic, and social pressures that threatened the intellectual independence of the individual.
Against these forces, freedom of thought was conceived as a safeguard for the inner dignity of the human person. Importantly, archival materials from the drafting process suggest that this right was understood as absolute. By this, Professor Bublitz clarified, the drafters meant that the right was not subject to ordinary balancing against competing state interests.
However, despite this strong commitment, the drafters never fully defined the scope of the right. What precisely counts as “thought”? What kinds of influence or intervention violate freedom of thought? These questions remained largely unresolved. For decades, this ambiguity has posed little practical difficulty. The human mind remained largely inaccessible to external technological control. That situation is now changing. Recent advances in neuroscience and artificial intelligence are transforming what is technologically possible. Professor Bublitz highlighted two principal modes through which neurotechnologies operate.
First, some technologies measure neural signals. For example, through electrical or magnetic monitoring, and use computational methods to infer mental states. These technologies aim to decode information about perception, intention, or internal speech from brain activity. Second, other technologies intervene directly in neural processes, through electrical stimulation, ultrasound, or pharmacological methods, in order to alter cognitive or emotional states. These developments raise profound legal and ethical questions because they map directly onto two potential threats to freedom of thought: the non-consensual revelation of unexpressed thoughts and the non-consensual alteration of mental processes.
Although current technologies remain limited and highly dependent on controlled conditions, research in brain decoding has progressed rapidly. Experimental systems have already demonstrated the capacity to reconstruct visual images or elements of inner speech from neural data under laboratory conditions. Meanwhile, interventions such as deep brain stimulation or emerging neuromodulation techniques show increasing potential to affect cognition, mood, and perception. These developments illuminate a deeper dimension of human vulnerability: the possibility that the internal mental sphere, the very domain that human rights law has historically sought to protect, may become technologically accessible.
A central question of the lecture was whether freedom of thought can still plausibly be defended as an absolute right. Critics point to a series of counterexamples intended to demonstrate that the right cannot be absolute. These include coercive psychiatric treatment, parental education of children, witness testimony obligations, and even hypothetical cases involving mental intervention in self-defence. Professor Bublitz addressed these challenges by proposing a more refined interpretation of the right’s scope. First, he suggested that freedom of thought represents what legal scholar Cass Sunstein calls an “incompletely theorized agreement.” The drafters clearly agreed that freedom of thought should be absolute, but they did not settle every detail of its application. Where agreement is incomplete, interpretation should preserve the core consensus while elaborating the unsettled elements. Second, he argued that many counterexamples can be addressed through general principles of law that operate in the background of legal systems. Duties associated with lawful conduct, such as testifying in court, may involve mental activity such as remembering, but they do not necessarily involve direct interference with the inner domain of thought itself. Third, he emphasized that freedom of thought contains an internal tension. The right protects not only non-interference but also the conditions for rational and autonomous thinking. In certain circumstances, such as severe psychosis, interventions may restore rather than undermine the conditions necessary for meaningful cognitive freedom. In such cases, the intervention may not fall within the absolute core of the right.
Professor Saberi’s commentary offered an important jurisprudential reflection on these arguments. While largely agreeing with Professor Bublitz’s historical and doctrinal interpretation, she raised a broader question: does describing a right as “absolute” necessarily ensure the protection of what the right seeks to safeguard?
Drawing on debates within international law, she noted that even norms described as possessing the highest legal status often encounter complexity in practice. Courts and adjudicative bodies frequently confront situations where multiple foundational principles interact. In such contexts, the formal language of absoluteness may not always determine outcomes. Her intervention therefore highlighted an important distinction between formal legal status and practical legal protection. The designation of freedom of thought as absolute may express a powerful normative commitment, but the real challenge lies in translating that commitment into meaningful safeguards in the face of emerging technological power. This discussion ultimately revealed how technological change is forcing a reconsideration of one of the most fundamental questions in human rights law: where does the legitimate reach of law end, and where does the protected inner life of the person begin?
Emerging technologies increasingly blur the line between internal and external domains. Digital systems shape attention, belief formation, and decision-making at unprecedented scale. Neurotechnologies promise new forms of access to mental states and new capacities for intervention. In this environment, freedom of thought can no longer remain an underdeveloped abstraction. It must be developed into a robust legal framework capable of addressing technologies that increasingly affect the human mind. At stake is not merely a doctrinal question within international law. It is a deeper question about how legal systems respond to the vulnerabilities of being human. If the human mind itself becomes susceptible to technological access and manipulation, then protecting freedom of thought may become one of the most important human rights challenges of the twenty-first century.