 The Saturāntika and the Theravāda developed alternative theories of causal conditioning in conjunction with their rejection of the Sarvāstivāda ontological model and their claim that dharmas exist only in the present. The Sautrāntika explained causal interaction among past and future dharmas by reference to the idea of “seeds” (bīja), or modifications in subsequent dharma series. The Sautrāntika theory of seeds is the precursor of two extremely important concepts of later Mahāyāna Buddhist thought, namely, the Yogācāra’s concepts of “store consciousness” (ālayavijñāna) and of Buddha-nature (tathāgatagarbha) (Cox 1995, 94–95; Gethin 1998, 222). The Theravāda theory of causal conditioning, as set out in the Paṭṭhāna, proposes a set of twenty-four conditional relations (paccaya) that account for all possible ways in which a phenomenon may function in conditioning the rise of another phenomenon. The twenty-four conditional relations are: 1) root cause (hetupaccaya); 2) object support; 3) predominance; 4) proximity; 5) contiguity; 6) simultaneity; 7) reciprocity; 8) support; 9) decisive support; 10) pre-existence 11) post-existence; 12) habitual cultivation; 13) karma; 14) fruition; 15) nutriment; 16) controlling faculty; 17) jhāna – a relation specific to meditation attainments; 18) path – a relation specific to the stages on the Buddhist path; 19) association; 20) dissociation; 21) presence; 22) absence; 23) disappearance; 24)  non-disappearance.[15]  The majority of the Theravāda twenty-four conditions have counterparts in the Sarvāstivāda theory and both systems show various other parallel interests and points of resemblance. The likelihood, then, is that the two systems originated before the two schools separated and continued to evolve after their separation (Conze 1962, 152–153; Kalupahana 1961, 173).