All phenomena, other than the result itself, which do not impede the production of the result. Some, such as the seed for a sprout, are potent acting causes (byed-rgyu nus-ldan); while others, such as the mother of the farmer who planted the seed, are impotent acting causes (byed-rgyu nus-med). One of the six types of causes outlined by Vasubandhu in "A Treasure House of Special Topics of Knowledge" (Chos mngon-pa'i mdzod, Skt. Abhidharmakosha).
J. Hopkins: Creative cause