Freedom of Opinion Is Freedom of Religion — Or Is It?

Conscience, Expression, and the Secular State

Figure 1. The inner forum may be absolute; the outer manifestation cannot be.

I. Introduction: The Liberal Promise and Its Tension

For John Stuart Mill, freedom of opinion was not an ornament of liberal society but one of its enabling conditions. In On Liberty, he formulated the principle with unmatched clarity: if all mankind but one were of the same opinion, mankind would have no greater right to silence that one person than that person would have to silence mankind.¹

Mill’s claim is radical because it reaches beyond tolerance into necessity. Freedom of opinion is not merely a right; it is an epistemic safeguard. A society that suppresses dissent does not merely commit injustice; it risks error, stagnation and, ultimately, decay.

Yet even within this liberal tradition, a tension emerges almost immediately. There is a fundamental difference between holding an opinion and expressing it; between believing something and acting upon it; between conscience and institution. The question is therefore unavoidable: can freedom of opinion be unlimited, while freedom of expression — and, by extension, freedom of religion — must be limited?

This essay argues that it must be so. Liberal societies are sustained by a crucial distinction between the inner domain of belief, which must remain inviolable, and the outer domain of manifestation, which inevitably enters the realm of power and must therefore be governed.

II. The Inner Forum: Opinion, Conscience and Belief

Modern legal and philosophical thought distinguishes between forum internum and forum externum. The former refers to the internal domain of thought, conscience and belief; the latter to their external expression and manifestation. This distinction is central to modern human-rights doctrine, especially in the interpretation of freedom of thought, conscience and religion under Article 18 of the International Covenant on Civil and Political Rights.²

The inner forum encompasses freedom of opinion, freedom of conscience and freedom of belief. These freedoms are, in principle, absolute. A state may coerce speech or action, but it cannot reliably coerce belief without destroying the very conditions under which truth can be sought. This insight runs from Spinoza through Mill to contemporary liberal theory.³

Spinoza argued that freedom to philosophise does not threaten the state but strengthens it. Mill, in turn, grounded freedom of opinion in the necessity of error correction: suppressed opinions may be true, partly true, or essential to keeping truth alive rather than turning it into dogma.

Thus, the inner forum is not merely a private refuge; it is a public good. It enables a society to learn, adapt and correct itself.

III. The Outer Forum: Expression, Religion and Power

The situation changes once belief is externalised. The outer forum includes freedom of expression, freedom of religion in its manifest forms, public communication and organised practice. Here, belief enters the social world. It interacts with others, competes for influence and — crucially — may exercise power.

Freedom of expression is therefore not unlimited. It may be restricted where it becomes incitement, coercion, intimidation, defamation, fraud or direct harm to others. The modern law of rights reflects this: Article 19 of the ICCPR protects opinion and expression, but it treats the holding of opinion and the expression of opinion differently.⁴

The same applies, mutatis mutandis, to religion. Freedom of religion is not merely freedom of belief; it is belief made social, ritual, communal and institutional. Religion, in its fully developed form, includes worship and ritual, teaching and transmission, community organisation, moral norms governing behaviour and, sometimes, legal and political claims.

At this point, religion is no longer confined to the inner forum. It becomes a social and potentially political force.

IV. Epistemic Freedom and Institutional Freedom

To sharpen the distinction, it is useful to differentiate between two manifestations of freedom. Epistemic freedom is the freedom to think, believe, doubt and interpret. It must remain nearly absolute, because coercion here destroys the conditions of truth. Institutional freedom is the freedom to organise, teach, enforce norms and exercise authority over others. It must be limited, because it creates structures of power.

The transition from the first to the second is decisive. Religion becomes politically relevant not when it is believed, but when it is institutionalised. At that point, it no longer concerns only the believer; it affects others — often profoundly.

This is why the question of religion in a secular state cannot be answered by saying that religion is merely private. Some religions are not merely private metaphysical doctrines. They contain law, hierarchy, education, gender norms, community discipline and claims to public authority. Once belief claims jurisdiction over conduct, it has entered the terrain of politics.

V. The Secular State and Its Paradox

The modern secular state is built upon a delicate equilibrium. It aims to guarantee freedom of religion while maintaining neutrality between competing beliefs. Yet this neutrality is often misunderstood. The state cannot be neutral between belief and coercion, equality and hierarchy, law and arbitrary authority.

This gives rise to what may be called the secular paradox: the state must remain neutral between beliefs, but it cannot remain neutral between power claims. Therefore, the secular state is not neutral toward religion as power. It is only neutral toward religion as belief.

Rawls’s idea of public reason is helpful here: coercive political decisions must be justifiable to citizens as free and equal, not merely to members of one comprehensive doctrine.⁵ Habermas’s post-secular approach points in a similar direction: religious citizens need not be excluded from public debate, but when religious claims shape coercive law, they must be capable of translation into generally accessible reasons.⁶

The state that fails to recognise this distinction, risks either suppressing legitimate belief or enabling forms of domination incompatible with equal citizenship.

VI. Is Total Freedom of Religion Possible?

If religion includes unrestricted authority over external behaviour, then total freedom of religion is incompatible with the secular state.

A liberal polity can guarantee the freedom to believe, the freedom to worship, the freedom to organise religious communities and the freedom to teach and transmit faith. But it cannot grant unlimited authority over civil law, coercive social practices, the status and rights of individuals, or the use of force. To do so would be to abandon its own constitutional foundations.

The boundary condition is therefore clear: no belief — religious or otherwise — may justify coercion that violates equal citizenship.

VII. Traditions and Schools of Thought

This tension has been addressed across several intellectual traditions. Classical liberalism, represented by Locke and Mill, emphasises toleration but limits religion where civil peace is threatened.⁷ Republican thought, represented by Rousseau, insists on civic unity and may subordinate religion to the general will.⁸ Strict secularism seeks to exclude religion from public authority to preserve neutrality. Liberal pluralism, associated with Rawls, Nussbaum and Laborde, argues that political institutions must protect conscience without allowing any comprehensive doctrine to dominate public power.⁹ Post-secular approaches, associated with Habermas and Taylor, permit religious voices in public discourse but insist that democratic law must remain justifiable to all citizens.¹⁰

These traditions differ in emphasis, but they converge on one point: the necessity of managing the boundary between belief and power.

VIII. Trust, Pluralism and the Limits of Coercion

A pluralistic society depends on a shared expectation: that no group will impose its ultimate beliefs through coercive power. This expectation is the basis of trust.

Without it, minorities fear domination, majorities fear fragmentation and institutions lose legitimacy. The distinction between inner belief and outer authority is therefore not merely legal. It is civilisational.

Trust in a pluralistic society does not require citizens to agree about ultimate truth. It requires them to trust that disagreement will not become domination. That is the moral achievement of the secular state at its best.

Hereby the tacit underlying assumption is made explicit, that only a secular state will be able to guarantee the civil liberties, we have fought for since the inception of the European Enlightenment Movement about 300 years ago. 

IX. Conclusion: Freedom, Power and the Limits of Religion

Freedom of opinion and freedom of belief belong to the inviolable inner domain of the human person. They are the conditions under which truth may be pursued and error corrected.

Freedom of expression and freedom of religion, by contrast, belong to the social world. They are indispensable, but not unlimited, because they may become instruments of power.

The task of the secular state is not to suppress belief, nor to privilege unbelief. It is to govern the boundary between belief and power in such a way that all citizens remain free and equal.

In the end, the distinction can be stated plainly: freedom of religion is not the freedom to rule in the name of God. It is the freedom to believe without being ruled in the name of someone else’s God.

Liberal societies do not fail because they protect belief too strongly. They fail when they fail to distinguish clearly between belief and power. Or even worse. if they can make that distinction but are unable to act decisively on any aberration.

As a political party, the Europeans of the Planet addresses the social world, which is the community of men, implemented as a secular state. That state is obliged to protect the inner domain. To keep the itself strictly secular however, it has to be vigilant against any attempts to encroach upon the public sphere and must take measures to prevent any adverse effects on it. 

Endnotes

1. Mill, J. S. (2003). On liberty. Yale University Press. Original passage in Chapter 2, ‘Of the Liberty of Thought and Discussion.’ ↩
   
   
2. United Nations Human Rights Committee. (1993). General Comment No. 22; United Nations. (1966). International Covenant on Civil and Political Rights, Article 18. ↩
   
   
3. Spinoza, B. (2007). Theological-political treatise; Mill, J. S. (2003). On liberty. ↩
   
   
4. United Nations. (1966). International Covenant on Civil and Political Rights, Article 19. ↩
   
   
5. Rawls, J. (1993). Political liberalism. Columbia University Press. ↩
   
   
6. Habermas, J. (2006). Religion in the public sphere. European Journal of Philosophy, 14(1), 1–25. ↩
   
   
7. Locke, J. (2010). A letter concerning toleration and other writings; Mill, J. S. (2003). On liberty. ↩
   
   
8. Rousseau, J.-J. (1997). The social contract and other later political writings. ↩
   
   
9. Rawls, J. (1993). Political liberalism; Nussbaum, M. C. (2008). Liberty of conscience; Laborde, C. (2017). Liberalism’s religion. ↩
   
   
10. Habermas, J. (2006). Religion in the public sphere; Taylor, C. (2007). A secular age. ↩

References — Annotated APA 7

1. Berlin, I. (1969). Two concepts of liberty. In I. Berlin, Four essays on liberty (pp. 118–172). Oxford University Press.

• Berlin’s distinction between negative and positive liberty clarifies why freedom from interference in belief must be treated differently from claims that may justify authority over others. It is especially useful when analysing the transition from inward conviction to institutional power.

2. Bhargava, R. (2006). Political secularism: Why it is needed and what can be learnt from its Indian version. Institute of Human Sciences.

• Bhargava’s model of ‘principled distance’ offers an alternative to both strict separation and religious establishment. The state may engage with religion, but only under public principles such as equality, liberty and non-domination.

3. Habermas, J. (2006). Religion in the public sphere. European Journal of Philosophy, 14(1), 1–25. https://doi.org/10.1111/j.1468-0378.2006.00241.x

• Habermas argues that religious voices may participate in democratic debate, but that religious claims must be translated into generally accessible reasons when they inform coercive law. This directly supports the essay’s distinction between belief and public power.

4. Laborde, C. (2017). Liberalism’s religion. Harvard University Press.

• Laborde asks whether religion deserves special legal treatment or should be treated as one conception of the good among others. Her work is central for distinguishing conscience, religion, equality and liberal neutrality.

5. Locke, J. (2010). A letter concerning toleration and other writings (M. Goldie, Ed.). Liberty Fund. (Original work published 1689)

• Locke provides the classical liberal foundation for religious toleration and the separation of civil authority from salvation. His exclusions also show that the liberal tradition has always recognised limits where religion threatens civil order.

6. Mill, J. S. (2003). On liberty. Yale University Press. (Original work published 1859)

• Mill’s defence of freedom of opinion is the essay’s philosophical starting point. His argument is epistemic as well as moral: dissent is necessary because suppressed opinions may be true, partly true or needed to keep truth alive.

7. Nussbaum, M. C. (2008). Liberty of conscience: In defense of America’s tradition of religious equality. Basic Books.

• Nussbaum reframes religious freedom as protection of conscience broadly, rather than as privilege for dominant religion. This supports the essay’s claim that freedom of belief is more fundamental than institutional religious freedom.

8. Rawls, J. (1993). Political liberalism. Columbia University Press.

• Rawls’s concept of public reason is essential for analysing religion in politics. Coercive political decisions must be justifiable to citizens as free and equal, not only to adherents of one comprehensive doctrine.

9. Rousseau, J.-J. (1997). The social contract and other later political writings (V. Gourevitch, Ed. & Trans.). Cambridge University Press. (Original work published 1762)

• Rousseau’s treatment of civil religion represents a contrasting tradition: civic unity may require limits on doctrines that undermine allegiance to the political community. It sharpens the essay’s account of religion as a political force.

10. Spinoza, B. (2007). Theological-political treatise (M. Silverthorne & J. Israel, Trans.). Cambridge University Press. (Original work published 1670)

• Spinoza defends freedom to philosophise while subordinating religious authority to civil peace. His work is foundational for the idea that belief should be free, but institutional religion must not override political order.

11. Taylor, C. (2007). A secular age. Harvard University Press.

• Taylor explains secularisation not merely as church-state separation but as a changed condition of belief in which faith becomes one option among others. This is useful for distinguishing belief, unbelief and public legitimacy in plural societies.

12. United Nations. (1966). International Covenant on Civil and Political Rights.

• Articles 18 and 19 provide the international-law backbone for the essay. They distinguish thought, conscience, religion, opinion and expression, and they show why inner freedom and external manifestation are treated differently.

13. United Nations Human Rights Committee. (1993). General Comment No. 22: Article 18 — Freedom of thought, conscience or religion.

• This is a key interpretive document. It makes explicit that internal freedom of thought, conscience, religion or belief is not subject to limitation, while manifestation may be restricted under defined conditions.

14. Council of Europe. (1950). European Convention on Human Rights.

• Article 9 protects freedom of thought, conscience and religion, including the right to manifest religion or belief. It is central for grounding the essay’s philosophical argument in European rights doctrine.

15. European Court of Human Rights. (2025). Guide on Article 9 of the European Convention on Human Rights: Freedom of thought, conscience and religion.

• The guide summarises case law on Article 9 and illustrates how courts operationalise the distinction between inner belief and outer manifestation in concrete conflicts.