Will, Volition
noun
You have an idea and you have intent to carry it out. This is your will and volition.
いし
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
自分が意志の弱い人間だってことは自覚してますよ。
I’m aware that I’m a weak-willed person.