(いし)

いし
noun
will, volition, intention
cognition
See also: 意思(いし) (intention (意思))
1. will, volition
The mental faculty by which one decides on actions. Determination to do something.
To have a strong will.
To respect the person's wishes.
意志(いし)(よわ)
To have a weak will.

意志(いし) refers to a person's will, determination, or resolve — the inner drive to act or achieve something. It emphasizes firmness of purpose.

Common collocations

Kanji distinction

In practice, 意志(いし) focuses on firmness and character, while 意思(いし) focuses on one's wishes or intentions in a specific situation.