four kalpas ［四劫］ ( shi-kō): In Buddhist cosmology, the four periods of time corresponding to the four stages in the cycle of formation, continuance, decline, and disintegration that a world is said to undergo. The four kalpas are explained in the Long Āgama Sutra and The Dharma Analysis Treasury. In the kalpa of formation, a world takes shape in space, and a variety of sentient beings appear on it. In the kalpa of continuance, living beings conduct their life-activities. In the kalpa of decline, the land is destroyed by natural disasters, and living beings gradually diminish and then disappear completely. In the kalpa of disintegration, complete destruction has taken place, and nothing exists. One complete cycle of the four kalpas is called a major kalpa. See also kalpa of continuance; kalpa of decline; kalpa of disintegration; kalpa of formation.