Many Buddhists in the Nikaya, Mahayana, and Vajrayana traditions consider there to be three type of Buddha: Samyaksam Buddha, Pratyeka Buddha, and Sravaka Buddha.
The three kinds of Buddha
All three types of Buddha achieve Nirvana, and may be called Arhats, or foe destroyers, but within the Mahayana tradition some people reserve the term Arhat for Sravaka Buddhas.
Samyaksam Buddhas (Pali: Samma-Sambuddha, also known in Mahayana as Bodhisattva Buddhas) gain Nirvana by their own efforts, without a teacher for the entire path. They may then lead others to enlightenment by teaching the Dharma in a time or world where it has been forgotten or has not been taught before, because a Samyaksam-Buddha does not depend upon a tradition that stretches back to a previous Samyaksam-Buddha, but instead discovers the path anew. The Historical Buddha, Siddhartha Gautama, is considered a Samyaksam-Buddha.
Pratyeka Buddhas (Pali: Pacceka-Buddha) are similar to Samyaksam-Buddhas in that they attain Nirvana, however unlike the Samyaksam-Buddha, they are unqualified to teach. In Mahayana traditions, Pratyeka-Buddhas may remain silent, keeping the discovered Dharma to themselves.
Sravaka Buddhas (Pali: Savaka-Buddhas) gain Nirvana by hearing the Dharma as passed on from a Samyaksam-Buddha. Mahayana and Vajrayana teachings hold that, after attaining enlightenment, Sravaka-Buddhas may also lead others to enlightenment, but cannot teach the Dharma in a time or world where it has been forgotten or has not been taught before, because their enlightenment is dependent on a tradition that stretches back to a Samyaksam-Buddha.
Skillful means rather than ultimate teaching
Significantly, the three types of Buddha appear only rarely in Theravada texts, while in contrast Mahayana literature frequently invokes these three archetypes. However, even within Mahayana traditions, the three types of Buddha do not necessarily correspond to an ultimate teaching, but rather one that fits within a program of skillful means (upaya) or expedient practices. Notably, chapter 3 of the Mahayana Lotus Sutra, compares the three types of Buddha to three vehicles, namely a goat cart, a deer cart, and an ox cart. That discussion is followed by the statement that Buddha "First… preaches the three vehicles to attract and guide living beings, but later he employs just the Great Vehicle to save them." That is Mahayana (meaning "greater vehicle" in Sanskrit, a description rejected by Theravadans) transcends the three types of Buddha, rather than corresponding to a method for attaining status as one of the types. In short, while the three-Buddhas archetype remains popular, it is not universal among Buddhists, some of whom maintain a tradition of ekayana , the single vehicle or direct path to awakening.
References
- The Ten Perfections, Thanissaro Bhikku, 1999; the first paragraph outlines the Theravada understanding of the Three Buddhas