A wheel is one of the oldest symbols in Buddhism. The eight-spoked Wheel of Dharma is an emblem of the teachings that flowed from Shakyamuni's enlightenment.
The Wheel of Life, described in the Introduction, also has ancient roots.
In Zen, a circle, complete in itself, without beginning or end, symbolizes ultimate oneness. Buddhism is not alone, of course, in recognizing the metaphorical resonance of wheels and circles. Joanna Macy writes:
The turning wheel is a powerful symbol of the mystery at the heart of life. Planets and solar systems and electrons in their orbits are wheels revolving within larger wheels, just as the hours and seasons of day and year rotate too, and the circulation of the blood in the body, and the vast hydrological cycles that sustain our living world.
Like the sacred hoop of the Native Americans and the round dances and mandalas of ancient peoples, the wheel reminds us that all is alive and moving, interconnected and intersecting.
Mandalas, circular diagrams of symbolic forms, have played many roles in Buddhism. In the main, mandalas are seen as blueprints for spiritual practice that leads eventually to liberation.
The most ambitious mandalas are cosmograms, intended to represent not only the highest states of consciousness but also the entire universe. In the influential Diamond World mandala, which contains 1,461 Buddhas and bodhisattvas, compassion is supposed to radiate outward from the center, while wisdom spirals inward toward the center.
Mandalas have been used over the centuries as objects of meditation, teaching devices, vehicles of initiation, and prayers for others' welfare.
There are majestic mandalas in stone, such as Borobudur in Java and half-forgotten geographic mandalas, such as the Kunisaki Peninsula in Japan. Traditionally, to make a mandala is itself a form of meditation.