be at the bottom of

cause, origin, source, principle, element; occasioner, prime mover, primum mobile; vera causa; author (producer); mainspring; agent; leaven; groundwork, foundation (support)., spring, fountain, well, font; fountainhead, spring head, wellhead; fons et origo, genesis; descent (paternity); remote cause; influence., pivot, hinge, turning point, lever, crux, fulcrum; key; proximate cause, causa causans; straw that breaks the camel's back., ground; reason, reason why; why and wherefore, rationale, occasion, derivation; final cause (intention); les dessous des cartes; undercurrents., rudiment; egg, germ, embryo, bud, root, radix, radical, etymon, nucleus, seed, stem, stock, stirps, trunk, tap-root, gemmule, radicle, semen, sperm., nest, cradle, nursery, womb, nidus, birthplace, hotbed., causality, causation; origination; production.

be the cause of; originate; give origin to, give rise to, give occasion to; cause, occasion, sow the seeds of, kindle, suscitate; bring on, bring to bring pass, bring about; produce; create; set up, set afloat, set on foot; found, broach, institute, lay the foundation of; lie at the root of., procure, induce, draw down, open the door to, superinduce, evoke, entail, operate; elicit, provoke., conduce to (tend to); contribute; have a hand in the pie, have a finger in the pie; determine, decide, turn the scale; have a common origin; derive its origin (effect).

caused; causal, original; primary, primitive, primordial; aboriginal; protogenal; radical; embryonic, embryotic; in embryo, in ovo; seminal, germinal; at the bottom of; connate, having a common origin.

because; behind the scenes.