"Reason and reason alone", it's a bit more complex than that, unfortunately. From Voltaire, Descartes (Le bon sens est la chose du monde la mieux partagée [1],

"Reason and reason alone", it's a bit more complex than that, unfortunately. From Voltaire, Descartes (Le bon sens est la chose du monde la mieux partagée [1], "Common sense is the best distributed commodity in the world, for everyone is convinced that they are well supplied with it, and even those who are the most difficult to please in everything else are not in the habit of desiring more of it than they have."), and others, Enlightenment has risen. And there is a rather pertinent critique of enlightenment, as in the Dialectic of Enlightenment [2] by Adorno and Horkheimer. For them, the Nazis also think they must purify the race because it's the most rational thing to do, even if they view as the best leader a brown-haired, weakly-mustached, average height methamphetamine abuser. [1] "Le bon sens est la chose du monde la mieux partagée : car chacun pense en être si bien pourvu, que ceux même qui sont les plus difficiles à contenter en toute autre chose, n'ont point coutume d'en désirer plus qu'ils en ont.", 1637, Descartes, Discours de la Méthode; the French, only their guillotines are sharper than their words. [2] https://en.wikipedia.org/wiki/Dialectic_of_Enlightenment https://en.wikipedia.org/wiki/Dialectic_of_Enlightenment