Although a fascination with the fourth dimension and the search for ways of depicting it have engaged artists for more than a century, only the computer makes such depiction truly possible. Using the computer as a tool, painter and sculptor Tony Robbin has devoted his life as an artist to this quest. Fourfield is both a record of that quest and an eloquent testament to the value of its fulfillment. The understanding and appreciation of space as presented in works of art have changed over the centuries, and Robbin suggests that the time is ripe for our perception of space to undergo another radical shift. He makes clear that "seeing" space in three dimensions is merely a culturally based assumption, no more and no less valid than apprehending space in any other way. This realization frees us to understand space much as a computer might--as fluid, ever changing, and dynamic. It has also freed Robbin to create exhilarating and amazing works, derived from his original blending of art, science, and mathematics. Fourfield is a firsthand account of the artist's visual, intellectual, and philosophical evolution, which has taken him from paintings in a traditional two-dimensional format to those in which rods extending from the canvas and the shadows they produce present a visual experience of four dimensions. Most recently, Robbin has created sculpture that incorporates quasicrystals ("crystals" made up of nonrepeating patterns) and whose appearance varies with the viewer's position and the orientation of light. This experimentation is suggesting startling new directions in architecture as well. To assist the reader in comprehending this seemingly magical world, Fourfield comes with an image of a pattern of four-dimensional cubes, known as hypercubes, and special glasses through which to view it. Also included is an order form for a diskette containing a number of the computer programs developed by Robbin as he explored the world of computers and art. Written with a voice of eloquence and clarity for anyone interested in art, science, mathematics, computers, or philosophy, Fourfield is, however, not for the timid. Just as Douglas Hofstadter's Godel, Escher, Bach and Robert Pirsig's Zen and the Art of Motorcycle Maintenance altered their readers' perceptions, readers of Fourfield will find their way of seeing the world changed forever.