William Willis' recent oil paintings at the Washington Project for the Arts are impressive on a number of levels. In the first place they are big, muscular works made at a time when abstract paintings of such scale are out of fashion. More important, most of the paintings "feel" big, which is to say that the unusual, weighty forms Willis deploys and even the adamantly physical way he applies and then scrapes away heavy layers of paint are fully appropriate to the size of the works.

But if, initially, one thinks of Abstract Expressionist painters such as Adolph Gottlieb or Norman Bluhm in the presence of these paintings, one quickly realizes that Willis, 42, has appropriated certain elements of Abstract Expressionism -- the density of surface, the insistence upon the tactile quality of the paint, the strong contrasts between figure and ground -- for his own singular purposes. His paintings invite thematic interpretation even before one reads titles ("Yoni Lingam," "Samadhi") that tell of his interest in the complex symbolism of Hindu philosophy and art.

The fundamental theme of the best paintings here is the idea of connection, usually between two very strong forms. In "The Screen," two dark, powerful, tendril-like or knife-like forms are engaged in a violent, mysterious encounter upon a spacious, and beautifully painted, gray and blue ground. In "Mukti (Liberation)," two similar forms, one a bilious green, the other a liquid steel blue enlivened by bright blue zigzag stripes, are locked in a similar encounter. To describe the ground in this painting as a thick stew of indigo blacks is to make it sound awful, but it is a tribute to Willis' skill and his strength of feeling that in reality it contributes significantly to the sense of primordial sexuality that pervades the painting. The imagery becomes explicit in "Yoni Lingam" and "Samadhi," which focus on powerfully painted Hindu symbols for male and female sexuality.

It is important to stress that viewers who, like me, rapidly lose their mental footing in the arcane, paradoxical universe of Hindu philosophy can appreciate these paintings as paintings. They are very strong visual statements with powerful psychological undertones. Other works center on large, fish-head forms, and these are, for some reason, less convincing. One recent painting, "Grace and Gravity," features a sea creature and two large seashells realistically depicted on a neutral, aqueous ground. Though not as powerfully unified as "The Screen" and other works, the painting perhaps suggests a fruitful new direction.

Willis has been exhibiting in Washington for more than a decade. This show, his best so far, continues through March 16. WPA, 400 Seventh St. NW, is open from 11 a.m. to 5 p.m. Tuesday through Saturday.