The film stars an ensemble cast, led by Topol, Georgia Brown, Edward Fox, John Gielgud, and Margaret Leighton.

Brecht's play was then-recently called a "masterpiece" by veteran theater critic Michael Billington, as Martin Esslin had in 1960.

Using the telescope, Galileo seeks to test the theories put forth by Nicolaus Copernicus that place the Sun – and not the Earth – at the center of universe.

But his new position does not come with the government protection he enjoyed in Venice, and his friends in the higher echelons of the Roman Catholic Church refuse to come to his aid when he is summoned before the Inquisition.

The play was produced in Los Angeles, California and then in New York City, with Laughton (a famed film actor) starring as Galileo.

As described by Raymond Benson, "The talent (directors, actors, designers, technicians) was asked to work at a reduced rate or at scale.

"[8] For Galileo, Losey and producer Ely Landau were able to secure several well-known actors for roles major and minor: For the 1947 stage production, Hanns Eisler composed music for a series of songs that were sung by a trio of boys at the beginning of each of the fourteen different scenes of the play.

Referring to the first production in Los Angeles, John Houseman said later, "Joe was to be the director of this, which really meant ... that actually Brecht would produce and direct himself with aid from Charles Laughton.

These included the use of a trio of young boys whose songs preview parts of the plot, and also the staging of Galileo's recantation against a shadow-filled white screen (cyclorama).

[19] Losey's opening shot, an overhead view of the film sound stage, also calls attention to the theatricality of the production.

Critic Tom Milne remarked that the "smooth theatrical continuity tends to blunt the raw edges of Brecht's distancing effects".

Roger Ebert wrote in 1975, "Brecht's Galileo bears only a sporadic resemblance to the facts of the great man's life.

But no matter: What Brecht was after, and what the new American Film Theater version of his play does a pretty good job of delivering, was a drama of ideas, not biography.

"[5] Vincent Canby noted particularly the "hugely theatrical scene in which the Pope (Michael Lonsdale) is being robed for an audience and trying not to give in to the Inquisitor's arguments to do something about Galileo.

"[10] Writing in 2012, Alex von Tunzelmann commented: "Adapted from Bertolt Brecht's intelligent, gutsy play, this film is a smart take on Galileo's life.

Jay Cocks, reviewing the film for Time in 1975, wrote: "Topol misses the role's strength, both in character and intellect.

"[23] Canby, writing in The New York Times in 1975, complained: "There is one problem with the film, and it is a major one; the casting of Topol in the title role ... although he's a big man he imparts no sense of intellectual heft. ...