Luis Buñuel was only 28 when he made Un Chien Andalou. It was his first film after a period working as an assistant director in French cinema, most notably for Jean Epstein. The film certainly reflects Buñuel's youth and his desire to shock conservative sensibilities. The film critic Jonathan Rosenbaum, an admirer of Buñuel, has nevertheless said that "the first two films of Buñuel [Un Chien Andalou and L'Age d'Or] are those of a spoiled rich kid, cosigned by his partner in entitlements Salvador Dali" (Rosenbaum). Thus, as Rosenbaum is pointing out there, Un Chien Andalou mostly lacks the social consciousness (particularly regarding poverty) evident in his later film Las hurdes (also known as Land Without Bread, 1933) and in the films he made in Mexico, most notably Los olvidados (also known as The Young and the Damned, 1950). Nevertheless, three abiding concerns of Buñuel's career appear in Un Chien Andalou: his interest in psychoanalysis and surrealism, his interest in entomology, and his concern with themes arising from his Spanish and Catholic upbringing.
Buñuel first read Freud during his time as a student in Madrid. As he says in his autobiography My Last Sigh, "my discovery of Freud, and particularly his theory of the unconscious, was crucial to me" (My Last Sigh, Chapter 19). We can see this influence in the way Un Chien Andalou seeks to mirror logic of the unconscious and of a dream. Thus, the ideas originally animating the film were Buñuel's dream of an eye being sliced and Dalí's dream of a hole in a hand with ants crawling out of it. Also, the process of automatic writing that Buñuel and Dalí employed—volleying ideas between each other, and vetoing any ideas that seemed rationally connected—mirrors the process of free association used in psychoanalysis in order to uncover the patient's unconscious ideas, fantasies, and desires. Indeed, most of the transitions between shots and scenes in Un Chien Andalou do not make sense according to standard narrative expectations, but can instead be analyzed in terms of Freud's concepts of condensation and displacement. (See the entries on "condensation" and "displacement" in the Glossary.)
Though the shots of a hole in a hand with ants crawling out of it allegedly originated from a dream of Dalí's, we can also see in these shots the influence of Buñuel's longstanding interest in entomology. This interest of Buñuel's is also evident in the shots of the death's-head moth near the end of the film. As a student at the University of Madrid, Buñuel took entomology courses at the Museo Nacional de Ciencias Naturales (National Museum of Natural Sciences) from the naturalist Ignacio Bolívar. Buñuel would also return to a kind of entomological investigation in the opening of his following (and last) collaboration with Dalí, L'Age d'Or (1930), with its documentary-like shots of scorpions fighting. Discussing the latter film, the writer Henry Miller said, “Buñuel, like an entomologist, has studied what we call love in order to expose beneath the ideology, the mythology, the platitudes and phraseologies the complete and bloody machinery of sex” (Begin 425).
Un Chien Andalou also reflects Buñuel's Catholic upbringing in Spain. This is perhaps most evident in the shots of the Marist Brothers being dragged with chords by the First Man (along with slabs, melons, and grand pianos with rotting donkeys on them). Indeed, the Catholic order of Marist Brothers was evidently on Buñuel's mind for a long time, as other titles that Buñuel and Dalí considered for the film were Go Marist (Vaya marista) and The Marist in the Crossbow (El Marista en la Ballesta) (Adamowiscz 11). Images of Marist priests recurred in Buñuel’s early poetry, including one poem satirizing the antics of two Marist priests (Adamowiscz 65-66). The rotting donkeys also reflect an experience from Buñuel's childhood in Spain, which Buñuel recounts in his autobiography My Last Sigh: "It was in Calanda that I had my first encounters with death, which along with profound religious faith and the awakening of sexuality constituted the dominating force of my adolescence. I remember walking one day in the olive grove with my father when a sickeningly sweet odor came to us on the breeze. A dead donkey lay about a hundred yards away, swollen and mangled, serving as a banquet for a dozen vultures, not to mention several dogs. The sight of it both attracted and repelled me...I stood there hypnotized, sensing that beyond this rotten carcass lay some obscure metaphysical significance" (My Last Sigh, Chapter 2).