The phrase that titles the present article is crucial to understand how Spinoza understood political problems. Using Quinto Curcio Rufo's quote, the Dutch philosopher transmitted it to us, not as political advice, but in a critical way, in order to prove that superstition is a political-affective dispositive that determines a specific form of practicing power through the affective manipulation and the perpetuation of the passive forms implied. Although there is no systematic treatment about this term, in this paper I analyse the history and etymology of superstition; I examine what Spinoza said about this concept, and finally, I argue that he understood superstition as a determined affective configuration that operates in a parasitic way, because it could not exist except in relation with other affects, joined to power forms, overlapping the others in a meta-affective way. My aim is to explain the political efficacy of superstition under a different light in the present capitalist moment, as an ars affectandi that, just like theology, seats its power in superstition; also considering its ethical, political, epistemics and aesthetics consequences.