The prime concern of Buddhism is our life-state, the joy or suffering we experience at each moment. This is always seen as an interaction between external conditions and inner tendencies; the same conditions (the same workplace, for example) that will be experienced by one person as unremitting misery may be a source of exhilarating challenge and satisfaction to another. Strengthening our inner state so that we are able to resist and even transform the most difficult and negative conditions is the purpose of Buddhist practice.
Based on his reading of the Lotus Sutra, the sixth-century Chinese Buddhist T'ien-t'ai developed a system that classifies human experience into ten states or "worlds." This Ten Worlds teaching was adopted and elaborated by Nichiren, who stressed the inner, subjective nature of these worlds: "As to the question of where exactly Hell and the Buddha exist, one sutra reads that Hell exists underground and another sutra says that the Buddha is in the west. However, closer examination reveals that both exist in our five-foot body."
What are these ten worlds, then? Ordered from the least to the most desirable, they are: Hell--a condition of despair in which one is completely overwhelmed by suffering; Hunger--a state dominated by deluded desire that can never be satisfied; Animality--an instinctual state of fearing the strong and bullying the weak; Anger--a state characterized by an unrestrained competitive urge to surpass and dominate others and often a pretence of being good and wise. These four states are referred to as the Four Evil Paths because of the destructive negativity that marks them.
Continuing, Humanity is a tranquil state marked by the ability to reason and make calm judgments. While fundamental to our identity as humans, this state can also represent a fragile balance that yields to one of the lower states when confronted with negative conditions. Rapture is a state of joy typically experienced when desire is fulfilled or suffering escaped. The worlds thus far are sometimes grouped together as the Six Lower Worlds. These are all basically reactions to changing external conditions in which we experience a lack of real freedom and autonomy.
What Buddhism refers to as the Four Noble States represent the effort to live with integrity, inner freedom and compassion. The world of Learning describes a condition of aspiration to enlightenment. Realization indicates the ability to perceive unaided the true nature of phenomena. Together, these are sometimes referred to as the Two Vehicles, as people manifesting these states are partially enlightened and free from some deluded desires. But these worlds can be very self-absorbed, and in many Buddhist texts we find the Buddha admonishing the people of the Two Vehicles for their selfishness and complacency.
The world of Bodhisattva is a state of compassion in which we overcome the restraints of egotism and work tirelessly for the welfare of others. Mahayana Buddhism in particular emphasizes the Bodhisattva as an ideal of human behavior. Buddhahood is a state of completeness and perfect freedom, in which one is able to savor a sense of unity with the fundamental life-force of the cosmos. For a person in the state of Buddhahood, everything--including the inevitable trials of illness, aging and death--can be experienced as an opportunity for joy and fulfillment. The inner life-state of Buddhahood makes itself visible through altruistic commitment and actions enacted in the world of Bodhisattva.
This brings us to a key aspect of Nichiren's understanding of the Ten Worlds: Each world contains within it the other nine. As he expresses it: "Even a heartless villain loves his wife and children. He too has a portion of the Bodhisattva world within him." Thus, the potential for enlightened wisdom and action represented by the world of Buddhahood continues to exist even within a person whose life is dominated by the lower life-states of Hell, Hunger or Animality.
The reverse is also true. The life-state of Buddhahood is not separate or discontinuous from the other nine worlds. Rather, the wisdom, vitality and courage of Buddhahood can infuse and transform the manner in which a tendency toward, for example, Anger, functions in a person's life. When Anger is directed by the compassion of the worlds of Buddhahood and Bodhisattva, it can be a vital force in challenging injustice and transforming human society.
The purpose of Buddhist practice--for Nichiren Buddhists the recitation of the phrase Nam-myoho-renge-kyo--is to bring forth the life-state of Buddhahood which can illuminate our lives and enable us to forge lasting value from our eternal journey through all the Ten Worlds.