| determinative factor(expression, reason, importance, significance) |
| dominant cause(expression, reason, importance, significance) |
| dominant factor(expression, reason, importance, significance) |
| driving factor(expression, reason, importance, significance) |
| first principle(expression, reason, importance, significance) |
| fundamental cause(expression, reason, importance, significance) |
| fundamental premise(expression, reason, importance, significance) |
| fundamental principle(expression, reason, importance, significance) |
| fundamental reason(expression, reason, importance, significance) |
| fundamental term(expression, reason, importance, significance) |
| game changer(expression, reason, importance, significance) |
| governing factor(expression, reason, importance, significance) |
| initial cause(expression, reason, importance, significance) |
| issue main reason(expression, reason, importance, significance) |
| key aspect(expression, reason, importance, significance) |
| key components(expression, detail, importance, element) |
| key condition(expression, reason, importance, significance) |
| key details(expression, part, detail, element, key) |
| key enabler(expression, reason, importance, significance) |
| key idea(expression, reason, importance, significance) |