YOU SAID:

I see the individual person as a free and responsible agent determining their own development through acts of the will

INTO JAPANESE

私は個人の人が自由意志の代理人であり、意志の行為を通じて自分の発展を決定する

BACK INTO ENGLISH

I am an individual who is an agent of free will and decides his development through act of will

INTO JAPANESE

私は自由意志の代理人であり、意志の行為を通じて彼の発展を決定する個人です

BACK INTO ENGLISH

I am an agent of free will and an individual who decides his development through actions of will

INTO JAPANESE

私は自由意志の代理人であり、意志の行動を通じて彼の発展を決める個人です

BACK INTO ENGLISH

I am an agent of free will and an individual who decides his development through actions of will