J.S. Mill’s free speech theory has long supported the liberal ideal that the best answer to bad speech is more speech. This paper argues that Mill’s defense relies on a particular and increasingly untenable view of human reason. He assumes that reason’s primary function is as an autonomous, truth-seeking faculty. But a growing body of research suggests otherwise: thinkers like Haidt (2012) and Mercier & Sperber (2017) argue that reason evolved primarily for social justification, not objective truth-seeking. This fault line, what I call the Continental Divide between Enlightenment and Social Views of Reason, should mediate how we evaluate free speech norms.
In today’s media landscape, information is curated by AI assisted algorithms not to inform but to engage. These algorithms “nudge” (Thaler & Sunstein, 2009) for attention, not accuracy. The Enlightenment View of reason—defended by thinkers like Pinker (2018 & 2021)—casts reason as primarily a powerful tool for truth-seeking and progress, best left free to operate in a marketplace of ideas. The Social View, advanced by researchers such as Haidt (2012), Mercier & Sperber (2017), and Greene (2013), argues that reason evolved primarily as a means of social justification, shaped more by identity and group dynamics than by the pursuit of truth. Kahneman (2011) further demonstrates how reason is prone to systematic biases. If public reason is to fulfill its truth-tracking potential, it must operate within epistemic environments designed to support that function. In hostile digital ecosystems, we are not merely misinformed; we are systematically and reliably being hacked, the public sphere hijacked, and rational discourse short-circuited.
This paper integrates classical political philosophy (Mill) and contemporary social epistemology (Nguyen), alongside empirical insights from behavioral and cognitive science. Methodologically, it offers a normative analysis of reason’s primary function and speech’s role within epistemic systems. I argue Mill’s framework remains normatively powerful, but only in properly designed epistemic ecosystems.
To preserve the value of free speech, we must construct environments that support rational discourse. Today’s disinformation economy is to public reason what fast food is to public health: engineered for maximal consumption, indifferent to long-term harm. This supports a call for epistemic engineering: the ethical design of information systems and institutions that sustain deliberation not subvert it.
As journalist and Nobel Peace Prize laureate Marie Ressa has argued, truth must be protected as a civic infrastructure, not just a personal virtue. Her call to “restore integrity to the information ecosystem” (Ressa, 2021) echoes the central premise of this paper: public reason cannot survive in an environment engineered for distortion. This paper argues that epistemic integrity is a moral and democratic imperative, and I offer a new governance tool to operationalize that value. Namely, to protect the public good of shared epistemic environments.
This contribution aligns with the Ethics and Integrity track by reframing public discourse as a systemically vulnerable space requiring moral infrastructure. It argues that platform governance, public policy, and institutional trust are essential to sustaining democratic life in pursuit of truth and the societal benefits it brings.