In the story Antigone, Antigone has a very strong-willed and independent personality. Her actions are based on what she believes is right. She gets this rock solid idea to do something and doesn't think about the consequences. She is very driven to go through with a plan for this idea. And no one will be able to convince her to not do anything. What is this called?
See tenacious and its synonyms: dogged, hard-nosed, indefatigable, persistent, relentless, resolute, single-minded, staunch, steadfast, stubborn, unshakable, unyielding
There is some difference in nuance between these, and some can be combined, e.g.
She displayed a dogged persistence toward achieving her objective.