strong-minded

— Recognising that we are strong-minded is not the same as accepting ourselves to be stubborn or obstinate.

— Then there was the widow of a deceased brother of Mr Martin Chuzzlewit, who being almost supernaturally disagreeable, and having a dreary face and a bony figure and a masculine voice, was, in right of these qualities, what is commonly called a strong-minded woman; and who, if she could, would have established her claim to the title, and have shown herself, mentally speaking, a perfect Samson, by shutting up her brother-in-law in a private madhouse, until he proved his complete sanity by loving her very much.