One of the most original films by Zanussi, the most complete form of a film essay. The reflections start with the Augustinian term "illumination". Its meaning is described at the beginning of the film by professor Tatarkiewicz himself as enlightenment, enhancement of thought, which allows the mind to recognise the truth. The plot is set in the 1960s and tells the story of Franciszek Retman, a country boy who devotes his passion to discovering the truth about the world, the sense of existence and finally about himself. At first, he turns to the exact sciences (physics, biology). Confronted with the reality, after a series of disappointments, Franciszek changes the direction of his passions - a fascination with exact sciences, the cosmos, and mountains - is replaced by introspection, questions about the essence of human nature, about the existence of the soul. The plot is just a part of this film collage. The artist included documentary footage, educative fragments, statements by researchers, and iconographic elements. Many intellectuals of the 1970s saw their own dilemmas in the film and identified with Franciszek, partially due to the excellent performance by the charismatic amateur, cinematographer - Stanisław Latałło.