Obstinate
Part of speech: adjective
Definition: Stubbornly adhering to an opinion, purpose, or course, usually with implied unreasonableness; persistent. Said of inanimate things not easily subdued or removed.
Example sentence: The liberally educated person is one who is able to resist the easy and preferred answers, not because he is obstinate but because he knows others worthy of consideration.
Strong-minded
Part of speech: adjective
Definition: Having a vigorous, independent will and views