In "The Last Leaf," why is it considered that the last leaf was Behrman's masterpiece?

The last leaf is considered Berhman’s masterpiece not because it was a technically beautiful work of art, or because it broke any social boundaries or experimented with style, but because it saved Johnsy’s life.  Johnsy, sick with pneumonia, had declared that when the last leaf had fallen off the tree outside her window, she would fall with it – it would be time for her to die.  The doctor himself told Sue that if a...

The last leaf is considered Berhman’s masterpiece not because it was a technically beautiful work of art, or because it broke any social boundaries or experimented with style, but because it saved Johnsy’s life.  Johnsy, sick with pneumonia, had declared that when the last leaf had fallen off the tree outside her window, she would fall with it – it would be time for her to die.  The doctor himself told Sue that if a patient had no will to live, there was little he could do at this point in her illness; Johnsy had given up.

Mr. Berhman is an old, unsuccessful painter who lives downstairs from the two girls, who drinks too much and who is constantly rambling on about how one day he will paint a masterpiece.  When Sue tells Mr. Berhman about Johnsy’s intentions, he cries in dismay, “’Are there such fools?  Do people die because leaves drop off a tree?...Why do you allow her to think such a thing?’”  He clearly believes the entire situation to be ridiculous, and feels just as strongly as Sue that Johnsy mustn’t die, fond as he is of the girls.  But while Sue works on her own painting in hopes that Johnsy will see it and reconsider – a representation of the last leaf on canvas – Berhman as well works through the night, creating art not in imitation of reality but as a replacement for reality itself.

Johnsy has a change of heart because of the perceived tenacity of the last leaf – its dogged resistance to the wind and the seasons makes her realize how silly she had been to want to die, and allowed her to hold on long enough for her sickness to wane.  Little does she know that the leaf itself is a fiction.

Mr. Behrman’s final painting, therefore, is not only a creative solution to a dismal problem, but is the embodiment of the healing powers of art.