The wisdom of the prudent [is] to understand his way: but the folly of fools [is] deceit.

通达人的智慧，在乎明白己道。愚昧人的愚妄，乃是诡诈。(或作自欺)。

youdao

When the equity market tumbled 40% and interest rates fell way below 6%, the folly of this advice was revealed.

当股市下跌40％，利率低于6％的方式，这是愚蠢的建议。

youdao

She is an internationally acclaimed Internet phenomenon and a symbol of the folly of underestimating people because of the way they look.

她是一个全球著名的网络现象和因为外表而愚蠢低估他人的标志。

youdao

Applying the same assumptions found in the current discussion of cyberspace as a domain to other domains helps to illustrate the folly of this way of thinking.

FORBES: A Domain Like Cyberspace