Mahayana
The Mahayana appears to have developed between the 1st Century BC to the 1st Century CE. About the 2nd Century CE Mahayana became clearly defined. Master Nagarjuna developed the Mahayana philosophy of Sunyata (emptiness) and proved that everything is 'Void' (not only the self) in a small text called Madhyamika-karika.
After the 1st Century CE., the Mahayanists took a definite stand and
only then the terms of Mahayana and Hinayana were introduced.
Around
the first century CE, teachings of a different style appeared. The
terms Mahayana and Hinayana appeared in the Saddharma Pundarika Sutra
or the Sutra of the Lotus of the Good Law. Of great influence to the
development of the Mahayana was Master Nagarjuna (2nd Century CE) who
is known for his profound teachings on the philosophy of emptiness.
About the 4th Century CE, the Masters Asanga and Vasubandhu wrote
enormous amount of works on Mahayana. The Mahayana teachings were
mainly written down in Sanskrit, and are now called the Mahayana Sutras.
A clear division arose between the schools following the
traditional teachings and Mahayana. Although the main philosophical
differences may be small, they have profound consequences for the
practices involved.
The Mahayana philosophy is based on the older
tradition and fully accepts these teachings, but not all traditional
interpretations.
One of the most important aspects is for example the traditional interpretation that Buddhahood can be achieved only by very few people. The Mahayana teaches instead that every sentient being (being with a mind) can become a Buddha, the only thing preventing our full enlightenment is the failure to improve one's own actions and state of mind.
The Mahayana tradition claims that all their sutras have been taught directly by Shakyamuni Buddha or have at least been inspired by the Buddha.
The main Mahayana motivation is to lead all sentient beings to
enlightenment. Liberation from cyclic existence (Nirvana) and
Buddhahood for oneself are regarded simply as fortunate by-products of
one's efforts to help all beings. In fact, the only possible motivation
with which one can become a Buddha is the altruistic wish to lead all
sentient beings away from suffering.
This motivation is reflected in taking an additional set of
vows, known as Bodhisattva vows on top of taking Refuge. The main vow
is to free all sentient beings from suffering. These vows are not taken
for this life only, but for all future lives as well, until this goal
is achieved. The main practices of a Mahayanist are summarised in the 6
perfections: the perfection of giving, ethics, patience, joyous effort,
concentration and wisdom.
The Mahayana tradition mainly developed in North India, and
spread further North into China and Tibet. In China, Buddhist
philosophy and practice was often mixed with Taoist and Confucian
aspects. Via China, Mahayana Buddhism also spread to other countries
like Korea, Vietnam, Cambodia, Laos and Japan.
Also, in China the Ch'an tradition evolved, which was introduced
into Japan, and there developed into Zen. Also, the very popular Pure
Land Buddhism developed, which focuses on being reborn in the Pure Land
of Amitabha, mainly through recitation of Amitabha Buddha's name. Pure
Land Buddhism is known as Jodo in Japan.
In contrast to the
current very clear division between Theravada and Mahayana schools, it
must be noted that for many centuries, monasteries in India were filled
with monks of both traditions. It was considered a very personal
decision to choose for individual liberation or Buddhahood.
The monastic and ordination rules are virtually the same, and the teachings overlap to a great extent. See for example this important text from the World Buddhist Sangha Council convened by Theravadins in Sri Lanka in 1966.