It is impossible to appreciate the nature and function of popular cinema in its heyday without an understanding of censorship. Alexander McGregor is the latest scholar to explore the role of censorship in 1930s Hollywood. Arguing that, during the 1930s, the American Catholic Church saw itself as at war with modern secular society and sought to control the cinema as a weapon with which to win the struggle to impose a pro-Catholic social moral code on the American population as a whole, he concludes that ‘no other agency played a more committed or vital role in the Kulturkampf of the long 1930s than the American Catholic Church’. There is plenty of evidence to support this contention. Catholics lobbied vociferously for the censorship of films and the Production Code adopted by the film industry in 1930 was written by two influential Catholics, Martin Quigley, editor and publisher of The Motion Picture Herald and Daniel Lord sj. The Production Code Administration (PCA), which vetted all Hollywood scripts, was headed by a devout Catholic, Joseph Ignatius Breen. The activities of the PCA were reinforced by the Catholic Legion of Decency, established in 1934, which rated all films as A (acceptable), B (objectionable in parts) or C (condemned). The twenty million American Catholics were forbidden under penalty of mortal sin to see the condemned films. The success of these agencies in controlling movie content is evidenced by the fact that in 1938 of the 535 films released, not one was rated C by the Legion, suggesting that they generally conformed to the precepts advanced by the Catholic Church. Using PCA files, the papers of leading Catholic commentators and contemporary journals, McGregor traces Catholic influence in four subject areas: religion, sexuality, war and diplomacy, and ‘the temporal world’ (including race, immigration and crime). He argues strongly for the advancing of a ‘Catholicised’ view of the world and its fusion with Americanism, some of its most positive advocates being ruggedly masculine Catholic priests, played by actors such as Spencer Tracy (Boys’ Town, San Francisco) and Pat O'Brien (Angels With Dirty Faces, The Fighting 69th). He sees a ‘Catholicised’ approach to sexuality in the bans on depictions of homosexuality, abortion, prostitution and nudity, and the insistence on compensatory moral values to counterbalance the depiction of illicit heterosexual relationships. He sees the hand of an anti-Communist, antisemitic hierarchy in the elimination of positive views of Communism and negative views of Nazism from the screen. Given the involvement of ethnic minorities in crime, McGregor identifies an approach in which good Catholics, Irish-Americans, are found on the side of the law as policemen and priests, and bad Catholics, Italian-Americans, are found among the criminals. This is not the first time that this story has been told. There are excellent in-depth accounts of the Catholic influence in Hollywood by James M. Skinner, Gregory D. Black, Frank Walsh and Thomas Doherty. The value of McGregor's book is its focus on a specific decade (the 1930s), its persuasive argument for the promotion of a ‘Catholicised’ Americanism, its thematic approach to the topics covered and its contextualisation of the censors’ attitudes in specific Catholic teachings.