Sāṃkhya Kārikā verse 31

svāṃ svāṃ pratipadyante paraspara-ākūta-hetukāṃ vṛttim | puruṣa-artha eva hetuḥ na kenacit kāryate karaṇam ||

sva - own; one's self, one's own, my own, thy own, his own, her own, our own, their ownprati - with regard to; towards, in the direction of; back, in return, again; in opposition to, against, countepadya - a way, path, roadparaspara - like one anotherākūta - incitement to activity; intention, purpose, wishhetu - cause, cause of; motive; reason forvṛtti - fluctuation; modification; turning; set in motion, course of action, behaviour, movement; activity, function; profession, mode of life or conduct, course of action, behaviourpuruṣa - animating principle, self, consciousness, spirit; a person, man, a human being; peopleartha - purpose, aim; sense, meaning, notion; thing, objecteva - indeed, truly, really; thus; so, just so, exactly sona - no; not; nor, neitherkenacit - whatsoever; with anyone; with. anythingkārya - an effect, result; to be made or done or practised or performed, practicable, feasible; to be caused to dokaraṇa - a helper, companion; instrument, means of action; doing, making, effecting, causing; the act of making, doing, producing, effecting