Many interpretations of the teachings developed within the monastic community. The Great Vehicle or Mahāyāna, represents a rather popular and radical approach to the Dharma.
One of the most significant figures in the emergence of Mahāyāna, was Nāgārjuna, an Indian monk and philosopher who stressed the importance of the concept of śūnyatā or emptiness. The teachings on emptiness explain the true nature of phenomena; they all lack a substantial existence and manifest or perish in the chain of dependent origination. The realisation of this truth is the highest attainment in Mahāyāna Buddhism.
In Mahāyāna, spiritual emancipation is not a privilege of the monks. The common goal of ordained and lay people is the attainment of Buddhahood. For the Great Vehicle, there is an infinite number of Buddhas. A Buddha is not just a man of the highest attainment who decides to become the teacher of humans and deities. Buddhahood is identical to the Ultimate Truth, a state beyond the limitations of time and space, dual thinking and illusion. Enlightenment is the domain of perfect wisdom and compassion. We all possess these inner qualities, but they are covered under the dirt of our various afflictions. Liberation comes when we are able to purify ourselves and manifest our inherent enlightened properties, our Buddha-nature.
In Mahāyāna Buddhism, genuine compassion is the most important virtue, and for this reason, the mind that strives for Enlightenment is also a mind that actively seeks the benefit of all sentient beings. A being with such strong aspirations is called a Bodhisattva. Bodhisattvas choose to receive birth in this world again ana again, in order to lead all sentient beings to the Dharma. In order to fulfill their wonderful vows, they incarnate in numerous world and take various forms. The most famous such being is Avalokiteśvara, the Bodhisattva of Compassion.
In the Bhāvanākrama, a precious meditation manual, the great Indian Buddhist philosopher and yogi, Kamalaśīla, writes: The Great Compassion of a Bodhisattva does not perish. Why is that? Because it precedes all else. Just as man’s breath precedes his ability to live, the Great Compassion of a Bodhisattva precedes his endowment with all the merit and knowledge of the Great Vehicle.
In the years that followed, the teachings of the Buddha were further systemised and within Mahāyāna Buddhism, various sub-schools flourished. In Japan, the most important sects were Kegon, Hossō, Tendai, Shingon, Jōdo, Zen and Nichiren Buddhism.