Pratidwandi (English: The Adversary, Siddharta and the City) is a 1970 Indian Bengali drama film written and directed by Satyajit Ray based on the novel by Sunil Gangopadhyay.

Pratidwandi tells the story of Siddharta, an educated middle-class man caught up in the turmoil of social unrest.

In such constant wandering in Calcutta, disintegrating relationships with his sister and a communist brother, his friendship with Keya is the only thing that keeps him sane.

Vincent Canby of The New York Times gave it 4.5 stars out of 5, calling it a "particularly moving comedy" in which the protagonist "seethes with rage about social injustices, about economic corruption, but he is powerless to express it.

"Satyajit Ray", he writes, "gives his nod of approval to world-wide counter-culture revolution, the revolt of youth against the stagnant older generation, and the social upheaval taking place in his beloved Calcutta.

He says it's because India has a different temperament after being oppressed so long by being colonized by the British and therefore the youth has to re-establish their own true identities before they can change things for the better."

" The message seemed accessible", he concludes, "but, perhaps, what was most inaccessible in this political drama, was Ray's wickedly droll sense of humor (like those timely placed X-rays to let us see the stark truth of reality).

"[5] Writing for Sight & Sound, Tom Milne, considered that "[t]oo much [...] ha[d] been made of the increasingly direct political involvement in [...] The Adversary", finding parallels with his previous films such as Mahanagar, Kanchenjungha and Jalsaghar.

[6] Derek Malcolm wrote that the film's "lyrical flashback technique [...] does not always work out too well" despite having some "superb passages" and "that elusive quality of looking as deeply under the surface of things as almost anyone" in his writing and direction.

[9] In 2012, filmmaker Ashim Ahluwalia included the film in his personal top ten (for "The Sight & Sound Top 50 Greatest Films of All Time" poll), writing: "Pratidwandi sees Ray drop his early style for a gritty hand-held Godardian romp through ’70s Calcutta.