Impressed by René Magritte’s submissions to the 1936 International Surrealist Exhibition, the collector Edward James invited the artist to paint canvases for the ballroom of his London home. In response, Magritte conceived On the Threshold of Liberty (in the collection of the Art Institute) and his now-famous Time Transfixed. The artist later explained this picture: "I decided to paint the image of a locomotive. . . . In order for its mystery to be evoked, another immediately familiar image without mystery— the image of a dining room fireplace—was joined." The surprising juxtaposition and scale of unrelated elements, heightened by Magritte’s precise realism, gives the picture its perplexity and allure. The artist transformed the stovepipe of a coalburning stove into a charging locomotive, situating the train in a fireplace vent so that it appears to be emerging from a railway tunnel. Magritte was unhappy with the English translation of the original French, La Durée poignardé, which literally means "ongoing time stabbed by a dagger." He hoped that the painting would be installed at the bottom of the collector’s staircase so that the train would "stab" guests on their way up to the ballroom. Ironically, James installed it over his fireplace instead.

— Entry, The Essential Guide, 2013, p.278.

René Magritte owed a direct debt to Giorgio de Chirico, whose work he first saw in 1922. This painting is one of Magritte's most compelling images. In it, the influence of de Chirico is apparent in a shared approach to the creation of mysterious and enigmatic images through incongruous juxtapositions of familiar objects; it is also evident in Magritte's adoption of some of de Chirico's motifs (the clock, the locomotive), as a comparison with de Chirico's The Philosopher's Conquest makes clear. Magritte has, however, given his own imprint to the ideas implicit in de Chirico's early paintings. His images are less complicated and more immediately comprehensible than de Chirico's. His brand of realism is more meticulous in both technique and composition. Magritte's emphasis on order is apparent in the uncluttered and precisely rendered surfaces, in the grid of moldings and frames that controls the com-position, and in details such as the smoke of the locomotive, which tidily disappears under the mantelpiece. There is an engaging coarseness and naiveté de Chirico's images that Magritte exchanged in this painting for clarity and immediacy. There is, nevertheless, nothing slavish about Magritte's realism, as illustrated by his deliberate omission, in his final composition, of the shadow of the candlestick on the right. A comparison of the painting with a preparatory sketch shows this and other small but significant changes, such as the enlargement of both the clock's face and the locomotive. In typically compulsive fashion, these two circular forms are made to share the same diameter.

In a letter of 1959, Magritte commented at length on this painting, emphasizing that his goal was to unveil or evoke "the mystery" of things "that seem familiar to us [out of error or habit]." Having decided on a locomotive as his subject, "the problem," he explained, was "how to paint this image so that it would evoke mystery." Magritte added, "The image of a locomotive is immediately familiar: its mystery is not perceived. In order for its mystery to be evoked, another immediately familiar image without mystery—the image of a dining room fireplace—was joined with the image of the locomotive." He also remarked that "the title La duree poignardee is itself an image (in words) joined to a painted image" and that Time Transfixed did not seem to him "a very accurate translation." Indeed, although the English title has the memorable quality that Magritte often sought, it is both more catchy and less forceful than the original French. It does not convey the sense of duration and passage through time in the word "duree" (duration) or the violent impact of something stabbed with a dagger in the word "poignardee" (stabbed).

—Entry, Margherita Andreotti, Art Institute of Chicago Museum Studies, Vol. 20, No. 2, The Joseph Winterbotham Collection at The Art Institute of Chicago (1994), p. 170-171.