“El arte no es un espejo para reflejar la realidad, sino un martillo para darle forma.”
Original
Art is not a mirror to hold up to society, but a hammer with which to shape it.
Mistakenly attributed to Vladimir Mayakovsky in The Political Psyche (1993) by Andrew Samuels, p. 9; mistakenly attributed to Brecht in Paulo Freire: A Critical Encounter (1993) by Peter McLaren and Peter Leonard, p. 80; variant translation: "Art is not a mirror held up to society, but a hammer with which to shape it."
First recorded in Leon Trotsky, Literature and Revolution (1924; edited by William Keach (2005), Ch. 4: Futurism, p. 120): "Art, it is said, is not a mirror, but a hammer: it does not reflect, it shapes."
Disputed
Citas similares

“«El mundo es más maleable de lo que piensas, y está esperando a que le des forma con un martillo».”
Sin fuentes

“Los espejos se emplean para verse la cara; el arte, para verse el alma.”
Atribuidas