Question

separation of church, state is is Montesquieu, Voltaire, Rousseau

Answer 1

Short answer: Voltaire is the clearest advocate of a strict separation of church and state; Montesquieu supported religious toleration and limiting clerical power as part of his broader institutional checks, while Rousseau did not endorse separation in the modern liberal sense and instead proposed a "civil religion" subordinated to the sovereign.

Details:
- Voltaire: Strongly attacked clerical privilege and defended religious toleration (famous slogan: "Écrasez l'infame" — "crush the infamous thing"). He argued that the state should restrain the church's social and political power and protect individual conscience.
- Montesquieu: In The Spirit of the Laws he argued for religious toleration and for institutional checks (separation of powers) so no single authority — including the church — could dominate. He favored limiting the political influence of religion, though his primary focus was constitutional arrangement rather than a doctrinal separation of church and state.
- Rousseau: In The Social Contract he worried that private religious sects could fragment the body politic and therefore proposed a "civil religion" to bind citizens to the state. He wanted religion to serve the general will, not be an independent social power — which is not the same as endorsing church/state separation.

If you want primary-source citations or a shorter comparison chart, I can provide them.