" But the main source of the naturalistic outlook is the political experience of the generation of 1848: the failure of the revolution, the suppression of the June insurrection and the seizure of power by Louis Napoleon. The disappointment of the democrats and the general disillusionment caused by these events finds its perfect expression in the philosophy of the objective, realistic, strictly empirical natural sciences. After the failure of all ideals, of all Utopias, the tendency is now to keep to the facts, to nothing but the facts. The political origins of naturalism explain in particular its anti-romantic and ethical features: the refusal to escape from reality and the demand for absolute honesty in the description of facts; the striving for impersonality and impassibility as the guarantees of objectivity and social solidarity; activism as the attitude intent not only on knowing and describing but on altering reality; the modernism which keeps to the present as the sole subject-of consequence; and, finally, its popular trend both in the choice of subject and in the choice of public. "

― Arnold Hauser , The Social History of Art: Volume 4: Naturalism, Impressionism, The Film Age