By The history of European influence on American modernism has long been a subject of keen critical interest on this side of the Atlantic, and it remains even today—nearly a century after the Armory Show introduced the European avant-garde to the American public. It’s a topic nearly every generation of American artists and critics feels compelled to re-examine and reflect upon. In recent times, moreover, it has also commanded a good deal of attention in Europe as American art—especially that of the Abstract Expressionist and Minimalist movements—has exerted a potent influence abroad. Yet I doubt that this sometimes touchy and divisive subject has ever been as brilliantly explored as it is now in “Monet to Matisse, Homer to Hartley: American Masters and Their European Muses,” which can be seen currently at the Portland (Maine) Museum of Art through October 17.

From both European and American perspectives, this exhibition and its catalog are exemplary in every respect. The selection of paintings could hardly be improved, either in aesthetic quality or historical scope, and the written commentaries are similarly marked by a high level of connoisseurship that is mercifully devoid of the kind of clotted prose that nowadays is such a punishment to read. Indeed, from the very first room in the show, where we encounter the bold juxtaposition of Frédéric Bazille’s painting of male swimmers in “Summer Scene,” 1869, and Thomas Eakins’ even more provocative “Swimming,” 1885, the visitor is put on notice that this exhibition will not be limited to a mere round up of familiar pictures. And the boldness of this unexpected comparison of two masterpieces on similarly suggestive subjects is underscored by the sheer volume of new information in Richard R. Brettell’s first-rate essay on “Eakins and the Male Nude in French Vanguard Painting, 1850– 1890,” in the catalog.

The curator of this remarkable exhibition, Carrie Haslett Bodzioney, has brought an unfailing eye, too, to the many other pairings that are the distinctive feature of “Monet to Matisse, Homer to Hartley: American Masters and Their European Muses”—among them, ocean surf paintings by Gustave Courbet and Winslow Homer, mountain landscapes by Paul Cézanne and Marsden Hartley, Cubist landscapes by Georges Braque and Max Weber, portraits by Renoir and George Bellows, and the surrealist-cum-abstract expressionist paintings of André Masson and Jackson Pollock. In fact, the modernist section of the show, with its comparisons of Francis Picabia and Joseph Stella, Joan Miró and Alexander Calder, Fernand Léger and Stuart Davis, and Henri Matisse and Milton Avery, closes the exhibition on the same high note that thrills us with that first encounter with Bazille and Eakins.

It is worth recalling, however, that on neither side of the Atlantic have such influences and similarities always been given a warm welcome. In the 1930s, the American regionalist painter Thomas Hart Benton, then at the height of his popularity, led an intensely chauvinistic campaign to discredit the influence of European modernism on American art. “In spite of all the cultivated whoopings to the contrary,” he declared, “art cannot be imported.” And about the influence of Pollock and other Abstract Expressionist painters on British painting in the 1950s, the English critic John Berger was positively phobic.

Still, I know of nothing on the European side that compares with the vitriolic article written in this country in the 1920s by Royal Cortissoz called “Ellis Island Art.” Cortissoz was then the influential art critic of The New York Herald Tribune. If only as a measure of how radically things have changed for the better in this country, an excerpt from Cortissoz’s diatribe is worth recalling: “The United States is invaded by aliens, thousands of whom constitute so many acute perils to the health of the body politic. Modernism is of precisely the same heterogeneous alien origin and is imperiling the republic of art in the same way. … Such movements—crude, crotchety, tasteless, abounding in arrogant assertion, making a fetich [sic] of ugliness and, above all else, rife in ignorance of the technical amenities. These movements have been promoted by types not yet fitted for their first papers in aesthetic naturalization—the makers of true Ellis Island art.”