(いし)

いし
noun
will, volition, intention
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.