Sciuscia, Bicycle Thieves, Miracle in Milan and Umberto D. are political films in the sense that they deal with problems which are subject to legislation and political control; but they offer no solutions and propagate no specific programme. Zavattini has spoken of the new style as "a moral discovery, an appeal to order" and the films themselves bear out that the impulse behind them is primarily a moral one. What remains remarkable about them as a group is that their moral passion, which was born of the war and could find expression only after the release from fascism, has grown in intensity with every film. (pp. 87-8)
De Sica's extraordinary tact with people enables him to get performances that are always real and dignified. Whether they are more than this must depend on the players chosen and in Umberto D. they sometimes fall short. In the scenes demanding strong emotional reactions, de Sica's unadorned method of observation occasionally leaves the players, as it were, too much on their own in the centre of the screen.
The best scenes in Umberto D. … have a purity of effect which gives them, in context, a profound poetic intensity. Although the episodes mount, in a dramatic sense, slowly, there is behind them a kind of passionate identification with the characters' human predicament which creates an extraordinary concentration. De Sica has brought his subject to the screen with a directness which springs from an inner conviction and faith in his characters. It gives the film, in spite of faults in execution, the unmistakable authority and completeness of a masterpiece. (p. 88)
Karel Reisz, "Film Reviews: 'Umberto D'," in Sight and Sound (copyright © 1953 by The British Film Institute), Vol. 23, No. 2, October-December, 1953, pp. 87-8.