 Within the Sarvāstivāda framework, material reality (rūpa-dharma) is reduced to discrete momentary atoms, and much attention is drawn to ontological and epistemological questions such as whether sense objects are real at any time, or whether atoms contribute separately or collectively to the generation of perception. Atomic reality is understood as constantly changing: what appears to us as a world made up of enduring substances with changing qualities is, in fact, a series of moments that arise and perish in rapid succession. This process is not random, but operates in accordance with the specific capability and function of each atom. The spirit of this atomistic analysis of material reality applies equally to mental reality: consciousness is understood as a succession of discrete consciousness moments that arise and cease extremely  rapidly.[10]  Thus, the ratio of change between material and mental phenomena in any given moment is one to one: they occur in perfect synchronicity (Kim 1999, 54). On this point the Sautrāntika agreed with the Sarvāstivāda.