idealistic
US /ˌaɪ.diː.əˈlɪs.tɪk/
UK /ˌaɪ.diː.əˈlɪs.tɪk/

1.
characterized by idealism; unrealistically aiming for perfection
:
•
He's very idealistic and believes everyone can live in peace.
•
Her idealistic views often clash with the harsh realities of politics.