Alfred Barr once described Jean Arp as a 'one-man laboratory for the discovery of new form' (quoted in James Thrall Soby, Arp (exhibition catalogue), The Museum of Modern Art, New York, 1958, p. 7). The present work is indeed an extraordinary example of the artist's ability to take inspiration from natural forms around him, whilst always managing to transcend the realm of the tangible. As the title suggests, this wonderfully organic and sensual sculpture is at the same time evocative of a human torso and of a mysterious lunar landscape. The dynamic of the work is derived from its seductive undulations and shadowy crevasses, resulting in a stark contrast between the concave and convex forms.

Francis M. Naumann wrote about the present work: 'In the spring of 1950, the year Human Lunar Spectral was conceived and produced, Arp likened his work to ancient Greek fragments. "Since my youth," Arp later told an interviewer, "my thought was nourished by the things of Mediterranean antiquity, the ancient Greeks impregnated me with their rhythms." [...] The first limestone version of Human Lunar Spectral was only eleven inches high, suggesting that it may have been inspired by an image of a comparable scale. The enlarged version, however (from which the Sisler bronze derives), was carved to a height of 35 inches, clearly intended to suggest human proportions' (F. M. Naumann, op. cit., p. 40).

The original plaster model for this work is now at the University of California, Los Angeles (UCLA). Another bronze cast is at the Stiftung Hans Arp und Sophie Taeuber-Arp, Rolandseck. A pink limestone version of the sculpture is in the collection of the Museo d'Arte Moderna in Rio de Janeiro, and a white marble version is in the Dotremont collection, Brussels. Arp also executed a smaller version of this work (28cm. high) in stone and bronze.