without; if it were not for
Conjunction meaning 'without' or 'if it were not for'. Often used in the pattern 〜なくして（は）〜ない, expressing that something cannot happen or exist without something else. Cross-referenced with 無くしては.
See also: なくしては
Success is impossible without effort.
Without your help, this work would not have been completed.
なければ is the conditional form of ない and means 'if not', while なくして is a conjunction that directly means 'without' and is used in more formal or written contexts.
without; if it were not for
Derived from the 連用形 (continuative form) of the classical adjective 無し (なし) plus the particle して, which together function as a conjunction meaning 'without'.