Use cunning, but do not abuse it.
xlv
cunning and should be utilized, but not abused. People should not appreciate it, much less boast about it. Anything artificial should be concealed, and cunning in particular is frowned upon. Deception is of great use. Therefore, our vigilance must be doubled. But it must not be out in the open. For it arouses distrust, causes much annoyance, evokes vengeance, and gives rise to more evil than we can imagine. To go about one's work with care is a great advantage in action, and there is no greater proof of wisdom. The greatest skill in any action lies in the proficiency with which it is performed with certainty.
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This page is auto-translated from /nishio/狡猾さを利用し、しかし乱用してはならない。. If you looks something interesting but the auto-translated English is not good enough to understand it, feel free to let me know at @nishio_en. I'm very happy to spread my thought to non-Japanese readers.