If you do not set yourself to do something, it shall not be accomplished, anything at all, What is not accomplished is what the person did not try to do. I will break it part by part: 為さねば If you don’t do (something) 為す to do（なす --> なさぬ --> なさねば) 成らぬ it won’t become, it won't be accomplished 何事も anything at all (なにごとも) 成らぬは What is not accomplished 人の為さぬなりけり is what the person did not do I found on the internet the original quote from the Edo jidai 為せば成る為さねばならぬ何事も成らぬは人の為さぬなりけり　 The language style in this sentence is typical in sayings. I think that in a common language style it could sound something like: やってみれば完成できる，やってみないと完成できない、何事も、 完成のないことは人のやってみなかったことですよ！ If you set yourself to do something, it shall be accomplished, anything at all, What is not accomplished is what the person did not try to do. なりけり is an old form to show admiration (like よ) You can see more explanations here: https://jpnculture.net/nasebanaru