Sometimes classified as Symbolist,[5] his phantasmagoric later works depicted Christian religious visions, elements of Classical mythology, and scenes inspired by the operas of Richard Wagner.

Slight in figure, nervous in manner, delicate in health, with regular features and an aristocratic expression, speaking English brokenly, but using it in preference to any other tongue….much of his life was spent in Spain and Italy, but his academic education was pursued at the celebrated Vaugirard College in Paris, under the direction of the Jesuits.

The American’s health was severely tried by the resolute ambition which made him simultaneously a collegian and an art-student; and, as if still further to test it, Vibert invited him to become a member of his family after the regular term of his atelier had closed, thus giving him an extraordinary opportunity for mastering the art that he loved.

"[11] Étienne Durand saw a depiction ofthe reverie of the principle figure dressed in red, a prince of the church…Around him, like motes populating a ray of sunshine, crowd together the most disparate visions, capable satisfying all human passions and appetites: love, ambition, avarice, sensuality, dissipation, etc.

In a corner, the divine child, sleeping in his crib, shines with a bright halo; above him, vague and diaphanous forms of celestial beings glide in the radiance of the stained glass windows.

It is a bizarre composition that seems at first sight incoherent, like a feverish hallucination, but which becomes clearer as one studies it and discovers, rendered with astonishing clarity, the moral kaleidoscope of meditation.

"So faulty in this matter is the design, the eye travels in puzzled and bewildered amazement…The discovery of the Christ-child…elucidates the mystery, but it in no wise explains why Mr. Marcius-Simons, who obviously has the gift of imagination, should be so wofully lacking in style.

"[18] These striking new works attracted the interest of the influential New York connoisseur and art dealer Samuel Putnam Avery, famous for having introduced the paintings of Turner to America.

By this time, the artist's style, tone, and subject matter had changed completely from his beginnings as a light-hearted genre painter, as exemplified by the nightmarish allegory Les Courtesanes.

"[21] The Art Collector noted wryly that the Marcius Simons (without a hyphen) who "commenced as a painter of genre" had emerged "full fledged into Pinckney Marcius-Simons, in quite another light.…He did so, says his biographer, after 'a serious illness,' which confined him to the solitude of his studio.

To judge from the results, it must have been a very serious illness indeed…"[22] But The New York Times, noting that the exhibit had "occasioned no little discussion and comment," said that Marcius-Simons' "ideas are entirely original, extremely personal, and of a curiously symbolic nature.

Little art of this order has as yet reached this city, but in Paris the Rose Croix and other exhibitions…have given the men of impressionistic ideas and methods free scope…The twenty pictures at Avery’s are exceedingly interesting…and in them are combinations of color effects entirely his own.

"Though the painter is very young," wrote The House Beautiful, "his reputation is firmly established as one of the most original and daring representatives of American art…the school of the Rose et Croix [and] all its eccentricities are willingly forgiven when one finds that it has rendered vocal the genius of such a man as Pinckney Marcius-Simons," whose works "have that strange clutch upon one's feelings that Turner's masterpieces had.

[48] In March 1904, Marcius-Simon, at his home in Paris, learned that his painting Where Light and Shadow Meet had been purchased by Teddy Roosevelt, then President of the United States.

In a letter dated March 8, Marcius-Simon wrote to Roosevelt: "It is hard for me to express adequately the great pleasure, the help in my life's work, that your appreciation of my art has been to me."

"As a painter, I stand at the point where the definition between music and pictorial art is lost.…Using the chromatic scale to produce new harmonies of shades and varieties of color, I create as I go, handling my palette to express thoughts through the medium of the painted objects."

He concluded, "Such being my convictions, my life struggle and my aim, you can imagine, Mr. President, what the revelation that you have long known and appreciated my efforts, though the possessions of friends, and that you now own one of the finest examples of my brush, has been to me.

"[50]Marcius-Simons followed up by dedicating to Mrs. Roosevelt and making a gift of his painting Victory, which he described as "the olive branch tendered to the world but enforced by the sword of justice and might beneath."

Edith Roosevelt described the painting in a letter to her sister Emily Carow: "The color is quite beautiful and the picture will always be interesting historically.

After the death of Marcius-Simons, Roosevelt wrote: Many Americans of wealth have rendered real service by bringing to this country collections of pictures by the masters of painting.

[53]Among his last works, created in the year before his death, was an extra-illustrated book: a copy of the Paul Meurice 1886 French translation of Shakespeare's A Midsummer Night's Dream covered inside and out with watercolors painted by Marcius-Simons in 1908, while in Bayreuth.

Considering that Marcius-Simons may have been in declining health at the time it was created, the decoration of this book would have provided a close-at-hand, even bed-ridden, means for him to express his art when unable to work on the large canvasses of his Wagnerian project.

George William Sheldon in 1888 described him as a man of twenty-five who looked "scarcely more than eighteen.…Slight in figure, nervous in manner, delicate in health, with regular features and an aristocratic expression.

"[1] Alexandre Hepp recounted a visit in 1896: "He receives me in a long brown dressing gown belted with a knotted cord, a bit like Balzac, with only his head and hands visible.

Louis Vauxcelles, paying a call on the artist in 1903, described "his emaciated face, his eyes shining with fever, his weary forehead, his wasted hands.

"[11] Speaking of his working habits, Marcius-Simons told Hepp he would sometimes put a canvas aside for three years and then, waking one morning, come back to it, painting automatically, as if another hand controlled his brush.