When the Barnes Foundation moved its art collection from Merion, Pennsylvania to a new space in downtown Philadelphia two years ago, it was careful to replicate the famously idiosyncratic galleries of its former home and added a side space for temporary exhibitions. The World Is an Apple: The Still Lifes of Paul Cézanne, displaying over twenty loaned artworks by the Postimpressionist master, is a newly opened special exhibition which Barnes Chief Curator Judith F. Dolkart says “complements and illuminates” the nearly seventy works by Paul Cézanne (1839-1906) on display in the foundation’s permanent collection.

A keen-eyed collector, Dr. Albert C. Barnes (1872-1951) was an early enthusiast of Cézanne’s art. Starting with a view of Mont Sainte-Victoire, purchased in 1912, Barnes amassed an unparalleled assortment of landscapes, portraits, still lifes and multiple figure compositions by Cézanne, including iconic canvases like “The Card Players,” 1890-1892, and the late masterpiece, “The Large Bathers,” 1895–1906.

There are more works by Cézanne at the Barnes Foundation than in all the museums in Paris combined. The Philadelphia Museum of Art has a number of important paintings by the Provençal painter, too, including a “Large Bathers” composition. By mounting the first exhibition devoted exclusively to the artist’s still lifes, organizers say the City of Brotherly Love, “the epicenter of Cézanne studies,” is enjoying “a marvelous Cézanne moment.”

According to curator Benedict Leca, for Cézanne, still life is “where he is experimental.” Indeed, the artworks in this exhibition contain wildly different compositional arrangements and display varied paint handling, showing Cézanne to be a thoughtful artist engaged in a lifetime of learning.

In the earliest still life here, “Sugar Bowl, Pears and Blue Cup,” c. 1866, the painter seems to be working his way through his influences. The fruits and ceramic ware in this canvas are described with wet-into-wet paint reminiscent of Édouard Manet’s (1832-1883) alla prima process, troweled on with a palette knife technique that brings to mind Gustave Courbet (1819-1877).

Another exploratory still life, “The Dark Blue Vase III,” c. 1880, looks informed by the Japonisme popular at the time among Impressionists. In this small, vertical canvas, stylized stems and flowers float above a china vase. The bottom edge of this picture, carefully painted to look unfinished, may give exhibition visitors pause, inviting viewers to rethink the numerous “unfinished” Cézannes as considered, complete works.

Beyond studio experiments, a few magnificent loans add heft to this show. The National Gallery of Art’s “Vase of Flowers,” 1900/1903, is bumpy from layer after layer of paint application, a testament to Cézanne’s tenacity. A busy canvas from the Musée d’Orsay, “The Kitchen Table,” 1888-1890, expertly juggles a lot of information, with fruits, cloth, ginger jar, pots and a basket teetering on a table, making for an unstill still life.

“Three Skulls on an Oriental Rug,” 1898-1905, also thick with paint from multiple revisions, is a powerful painting. Recalling his apprenticeship in the master’s Aix-en-Provence studio, artist Émile Bernard said: “The colors and shapes in this painting changed almost every day, and each day when I arrived at his studio it could have been taken from the easel and considered a finished work of art. In truth, his method of study was a meditation with a brush in his hand.”

Exhibition organizers suggest Cézanne turned to this macabre motif in response to his mother’s death in 1897. In “Three Skulls on an Oriental Rug,” the skulls wear haunted expressions as they sit in a cluster on a dark, patterned cloth. With no jawbones, the frightened skulls in this affecting picture seem to make muffled screams.

More than any of his contemporaries, Cézanne’s creative achievements dramatically altered the course of twentieth century art. His posthumous retrospective in 1907 at the Salon d’Automne is often cited as a seminal exhibition that led to the development of cubism. With these twenty additional still lifes there has never been a better time for Barnes Foundation visitors to get to know the artist Picasso called “the father of us all.”

The World Is an Apple: The Still Lifes of Paul Cézanne is on view through September 22, 2014, The Barnes Foundation, 2025 Benjamin Franklin Parkway, Philadelphia, PA, 215-278-7000, www.barnesfoundation.org

More information about Xico Greenwald’s work can be found at xicogreenwald.com