In today’s polarized political climate, researchers who combat mistruths have come under attack and been labelled as unelected arbiters of truth. But the fight against misinformation is valid, warranted and urgently required.

We argue that acquiescence in the face of widespread misinformation and dismissal of the prospect that information can ever be confidently classified as true or false are morally troubling choices. The fact that veracity is often conceptualized better as a continuum than as a dichotomy, and that some claims cannot be unambiguously classified as true or false, must not detract from the reality that there are many incontrovertible historical and scientific facts.

The idea that misinformation cannot be reliably identified is often accompanied by claims that it is premature to conclude that there is a problem, and therefore premature to act. This argument is familiar, it was used in the decades-long campaigns led by the tobacco and fossil-fuel industries to delay regulation and mitigative action. However, there is sufficient firmly established scientific knowledge to warrant both concern about misinformation and widespread deployment of countermeasures.

Public-facing communicators at all levels — including governments, non-governmental organizations, the media and the research community — should be encouraged to distribute evidence-based information and counter misinformation when it is deemed likely to be harmful.

Crucially, efforts to keep public discourse grounded in evidence will not only help to protect citizens from manipulation and the formation of false beliefs but also safeguard democracy more generally.