At the beginning of 1910, he moved to Florence where he painted the first of his 'Metaphysical Town Square' series, The Enigma of an Autumn Afternoon, after the revelation he felt in Piazza Santa Croce.

The paintings de Chirico produced between 1909 and 1919, his metaphysical period, are characterized by haunted, brooding moods evoked by their images.

At the start of this period, his subjects were motionless cityscapes inspired by the bright daylight of Mediterranean cities, but gradually he turned his attention to studies of cluttered storerooms, sometimes inhabited by mannequin-like hybrid figures.

"[15] Metaphysical art combined everyday reality with mythology, and evoked inexplicable moods of nostalgia, tense expectation, and estrangement.

The shop windows of that town inspired a series of paintings that feature biscuits, maps, and geometric constructions in indoor settings.

[19] This article heralded an abrupt change in his artistic orientation, as he adopted a classicizing manner inspired by such old masters as Raphael and Signorelli, and became part of the post-war return to order in the arts.

[20] In the early 1920s, the Surrealist writer André Breton discovered one of de Chirico's metaphysical paintings on display in Guillaume's Paris gallery, and was enthralled.

[21] Numerous young artists who were similarly affected by de Chirico's imagery became the core of the Paris Surrealist group centered around Breton.

The artist, far from willing to achieve realism in his paintings, strives to create images charged with myths and visions, for an art that is still literally "metaphysical", beyond reality.

In them he developed a repertoire of motifs—empty arcades, towers, elongated shadows, mannequins, and trains among others—that he arranged to create "images of forlornness and emptiness" that paradoxically also convey a feeling of "power and freedom".

[30] According to Sanford Schwartz, de Chirico—whose father was a railroad engineer—painted images that suggest "the way you take in buildings and vistas from the perspective of a train window.

In The Joy of Return, 1915, de Chirico's train has once more entered the city ... a bright ball of vapor hovers directly above its smokestack.

[32]In this, he resembles his more representational American contemporary, Edward Hopper: their pictures' low sunlight, their deep and often irrational shadows, their empty walkways and portentous silences creating an enigmatic visual poetry.

"[34] Other artists as diverse as Giorgio Morandi, Carlo Carrà, Paul Delvaux, Carel Willink, Harue Koga, Philip Guston, Andy Warhol and Mark Kostabi were influenced by de Chirico.

The choice was made to capitalize on Monk's popularity with intellectual and bohemian fans from venues such as the Five Spot Café, where the album had been recorded, but Monk biographer Robin Kelley later observed deeper connections between the painting and the pianist's music; Rimbaud had "called on the artist to be a seer in order to plumb the depths of the unconscious in the quest for clairvoyance ...

The architectural forms and the placement of the chalkboard evoked the unity of art and science—a perfect symbol for an artist whose music has been called 'mathematical.

'"[37] Writers who have appreciated de Chirico include John Ashbery, who has called Hebdomeros "probably ... the finest [major work of Surrealist fiction].

[39] In his book Blizzard of One Mark Strand included a poetic diptych called "Two de Chiricos": "The Philosopher's Conquest" and "The Disquieting Muses".

[43][44][45] The box art for Fumito Ueda's PlayStation 2 game Ico sold in Japan and Europe was strongly influenced by de Chirico.

[46] The cover art of New Order's single "Thieves Like Us" is based on de Chirico's painting The Evil Genius of a King.

[48] A 2018 study by researchers from the Magna Græcia University, published in Frontiers in Neurology, suggested that de Chirico suffered from Alice in Wonderland syndrome (AIWS),[49] a neurological disorder affecting a person's perception, leading the individual to perceive the sizes of some parts of their body and other objects, in an unreal way, like Alice in Lewis Carroll's novel.