Ideas are not dangerous unless they find seeding place in some earth more profound than the mind…. dangerous only when planted in unease and disquietude. But being so planted, growing in such earth, it ceases to be idea and becomes emotion and then religion. 

John Steinbeck,  The Log from the Sea of Cortez

Umberto Eco on religion

People are never so completely and enthusiastically evil as when they act out of religious conviction.

Umberto Eco, The Prague Cemetery

Umberto Eco on conspiracy

Who knows how many ... people in this world still think they are being threatened by some conspiracy? Here's a form to be filled out at will, by each person with his own conspiracy.... What does everyone desire, and desire more fervently the more wretched and unfortunate they are? To earn money easily, to have power (the enormous pleasure in commanding and humiliating your fellow man) and to avenge every wrong suffered (everyone in life has suffered at least one wrong, however small it might be).... But why; everybody asks, am I not blessed by fortune (or at least not as blessed as I would like to be)? Why have I not been favored like others who are less deserving? No one believes their misfortunes are attributable to any shortcomings of their own; that is why they must find a culprit..... [T]he explanation for their failure. It was some one else... who planned your ruin. 

Umberto Eco, The Prague Cemetery

The first step in dealing with the madness of the political world is not to let it make you crazy.... Fanaticism always seems foolish until it locks you up.

Adam Gopnik, Mixed Up: Montaigne On Trial (New Yorker, Jan 16, 2017)

Human beings ... may be divided simply into those who know they are acting and those who do not. True philosophers belong to the first group. The second encompasses, among others, utopian capitalists and Communists, the fanatics of the religious wars of the seventeenth century and the jihadists of the twenty-first.

David Bromwich, "Are We ‘Exceptionally Rapacious Primates’?", The New York Review of Books (November 5, 2015)