A comparative study of the right to freedom of thought in the context of emerging technologies, by Bethany Shiner and Patrick O’Callaghan

This blog post is based on a comparative study of the right to freedom of thought co-edited by the authors and published in a double special issue of the European Journal of Comparative Law and Governance. The blog post draws in particular on the introduction to the special issue and the article on the right to freedom of thought in the ECHR. This blog post seeks to outline why the right to freedom of thought has the potential to offer protection for mental autonomy in the context of certain emerging technologies.  

The Right to Freedom of Thought

The right to freedom of thought, though enshrined in numerous international, regional, and national legal instruments, has traditionally been understood to be of symbolic importance only. This is unsurprising since, until recently at least, few could imagine how an individual’s internal mental state, or forum internum, could be intruded upon. As Chief Justice Bryan of the Court of Common Pleas put it in 1477: “It is common learning that the thought of man is not triable, for the Devil knows not the thought of man.” Moreover, once thoughts are manifested in the forum externum through speech or action, they fall under the protective remit of a range of other rights e.g. freedom of expression, freedom of religion, freedom of conscience or freedom of association. In addition, unlawful attempts to extract a person’s thoughts through interrogation have long been associated with practices already forbidden under the prohibition on torture and cruel and degrading treatment. Against this background, it is understandable that some have queried the practical relevance of a right to freedom of thought.

As valid as this reasoning may be, it is outdated. No longer can the right to freedom of thought be dismissed as a right without utility. Policymakers, scholars and practitioners are starting to realise that the right to freedom of thought can offer protection against technologies that are capable of monitoring, recording, reading and analysing human thought. In particular, the absolute nature of the right means it has potential use in the regulatory and human rights contexts. Stating that the right to freedom of thought provides absolute protection to internally held thoughts would be trite and tautological were it not for the fact that technologies are being created and utilised (often for commercial gain) for the very purpose of reading, recording and influencing such thoughts. The absolute nature of the right to freedom of unmanifested thoughts, therefore, is a critical feature of the protective legal framework, notwithstanding that the absoluteness of the right is not without legal complexity.

In what follows, we pay closer attention to two broad ways in which emerging technologies have the potential to violate the forum internum.


Developments in neuroscience over the past fifteen years or so have provided an increased ability to monitor and influence mental processes. As neural activity patterns are a unique and unmistakable brain signal indicating a specific thought, once neural activity patterns are identified, through machine learning techniques, it becomes possible to infer what someone is thinking. However, there remain significant methodological challenges to developing more accurate ‘mind-reading’ technologies meaning it is not possible to read the random thoughts of individuals. Yet, the science is rapidly developing. It has already been shown that brain scanning can suggest an individual’s political orientation, implanted brain sensors can enable a paralysed person to walk by controlling an exoskeleton suit with thoughts, and applying statistical pattern recognition techniques to brain activity may determine whether a person is lying or telling the truth. Even more radical are experiments which seek to change behaviours or modify memories by implanting new memories into the minds of non-human animals. So, not only does it appear increasingly possible to understand what an individual is thinking, it may also be possible to alter the content of the mind.

It is already possible to buy various cognitive-enhancement devices that monitor neural activity and provide feedback to the user based on an analysis of the data collected by the device. Furthermore, numerous brain-computer interfaces, invasive and non-invasive, are being developed for health benefits and commercial gain alike which will all operate on thoughts to control external devices. In this context, although for the purpose of the right to freedom of thought, what counts as a thought has not been precisely determined, it may be broad enough to include neural activity more generally as well as conscious thoughts.

Algorithmic Processes

There is growing awareness that the high rate of data collection and analysis for use in algorithmic decision-making in our everyday lives might undermine human autonomy – the basis, it may be argued, for the right to freedom of thought itself. As the Declaration by Council of Europe’s Committee of Ministers on the manipulative capabilities of algorithmic processes observes, “(f)ine grained, sub-conscious and personalised levels of algorithmic persuasion may have significant effects on the cognitive autonomy of individuals and their right to form opinions and take independent decisions”. If this is possible then the exercise of individual autonomy is undermined on a daily basis and on a global scale.

That such concerns have particular potency in politics, through microtargeted political advertisements or video search and recommender algorithms, is also deserving of increased attention but there still has not been a single case before the European Court of Human Rights, the Inter-American Court of Human Rights nor the Supreme Courts of the US or the UK that engages with the question of whether, and to what extent, algorithmic decision-making might be undermining the free exercise of our political agency. In 2019 the Spanish Constitutional Court held that Spanish laws providing broad permission for political parties to collect and use voter data for campaign activities were unconstitutional because they violated the right to personal data protection, privacy and the ‘right to ideological freedom’ – which we can understand as a right to freedom of thought – and, importantly, the right to political participation. In this case, we see a recognition of the relationship between data collection, democratic participation, and freedom of thought in the sense of making determinations or decisions based on available information.

A comparative perspective

The co-edited double special issue of the European Journal of Comparative Law and Governance examines the right in the UK, Ireland, Canada, the USA and within the regional jurisdictions of the European Court of Human Rights and the Inter-American Court of Human Rights.

In the UK, the jurisprudence is dominated by freedom of religion and philosophical belief under the Equality Act 2010 where there is no explicit mention of freedom of thought but there is some protection for the manifestation of certain thoughts. In Ireland, the constitutional doctrine of unenumerated rights is the means through which the right to freedom of thought may be recognised outside of Article 9 ECHR. The contribution on the right to freedom of thought within the ECHR looks beyond Article 9 to include Articles 8, 10 and 11 ECHR in its analysis. This matrix of rights provides the conditions for the greatest enjoyment of the broad right to freedom of thought – a freedom that is enjoyed by the autonomous individual whose dignity is respected by the community. The ECHR contribution also tackles the question of when the right to freedom of thought ought to be regarded as offering absolute protection and when it offers qualified protection.

Freedom of thought is not recognised as an absolute right in any of the remaining jurisdictions featured in this special issue. The Canadian Constitution explicitly recognises the right to freedom of thought but not as an absolute right, for there is no such thing in that jurisdiction. In the USA, the right to freedom of thought is not explicitly mentioned but has been conflated with freedom of speech contained in the First Amendment to the US Constitution. Article 13 of the American Convention on Human Rights has conceived of freedom of thought and expression more broadly than the ECHR as it refers to three rights: freedom of thought, freedom of expression and the right to information. Further, the Inter-American Court understands the right as containing both collective and individual rights: a dual dimension. The individual dimension consists of the right of each person to express her own thoughts, ideas and information, and a collective or social dimension consists of society’s right to obtain and receive any information, to know the thoughts and ideas of others, and to be well-informed.


In the context of neurotechnology, lawmakers, bio-ethicists and neuroscientists argue that new neuro-rights are needed to protect human agency and cognitive autonomy in the face of emerging neuro-technologies that can intrude upon the forum internum. But is this really necessary? Protection already exists in the form of the right to freedom of thought, which can provide the protection sought and has the benefit of already sitting within developed legal frameworks with mechanisms for oversight and adjudication, as the special issue illustrates.

Posted by Bethany Shiner, Lecturer in Law, Middlesex University and DPhil Candidate, University of Oxford and Patrick O’Callaghan, Lecturer in Law, University College Cork