Christianity was the vehicle by which separation of church and state was accomplished.

Judge as of 2021-11 as a historical-causal claim. True: mainstream historical scholarship broadly holds that Christianity, through doctrines such as 'render unto Caesar' or the two-swords/two-kingdoms ideas, was the principal vehicle by which church and state were separated. Mostly true: scholars widely credit Christian ideas and institutions as a major contributor, though not the sole one. Mixed: scholarship is genuinely divided, with substantial weight also given to Enlightenment secularism, the religious wars and other factors. Mostly false: Christianity is seen as at most a background contributor, and the claim overstates it as 'the vehicle'; this also applies if the claim is presented as established but is not supported. False: the evidence shows that separation came about mainly in opposition to Christian institutions, with Christianity not a meaningful vehicle.

Set before the research began.

1. E1 Christianity - Separation, Church, State Britannica · 19 October 2026

   “It was achieved as a result of ideas arising from opposition to the English episcopal system and the English throne as well as from the ideals of the Enlightenment.”

2. E2 Historical Antecedents of Separationism Oxford Academic (Cornell Scholarship Online), chapter by Steven K. Green · 15 March 2022

   “This chapter traces the various historical antecedents for the idea of separation of church and state, both religious and secular. It discusses the Free Church movement arising out of the Reformation and the writings of the Enlightenment and Whig theorists of the eighteenth century.”

3. E3 [PDF] Rethinking Secularism - LSE Research Online LSE Research Online (Craig Calhoun, The Hedgehog Review 12(3), 2010) · 2010

   “It shapes centuries of struggle over papal and monarchical power, and ultimately issues with Marsilius of Padua in the doctrine of the Two Swords.”

4. E4 Overcoming the Wars of Religion: The Enlightenment and the Constitutional Enshrinement of Institutional Secularism Oxford Academic (Politicized Religion and the Reframing of Fundamental Rights) · 1 April 2026

   “This chapter explores the historical and theoretical foundations of institutional secularism.”

Britannica (E1) says separation came from ideas that arose in opposition to the English episcopal system and throne, and from Enlightenment ideals. Green's chapter (E2) traces the idea to both religious sources (the Reformation-era Free Church movement) and secular ones (Enlightenment and Whig writers). Calhoun (E3) links the Christian Two Swords doctrine to centuries of struggle over papal and monarchical power. So the sources give real weight to Christian ideas and movements, but also substantial weight to Enlightenment and secular factors. That matches the "mixed" criterion better than the claim that Christianity was "the vehicle."