volition

他完全是出于自己的意愿选择了这条职业道路。

He chose this career path entirely of his own ___volition.

她完全是出于自愿报名参加慈善跑的，没有任何人劝她。

She signed up for the charity run entirely of her own ___volition, with no one persuading her.

争吵过后，没等任何人要求，他就主动道歉了。

After the argument, he apologized of his own ___volition before anyone could ask him to.