I think people underestimate Aragorns force of will as a man. People always talk about how Sam was the strongest will next to Frodo considering that he had the ring when he thought Frodo died and gave it back to him. But people forget that Sam hesitates because he already feels the will of the ring telling him not to give it to Frodo. Aragorn on the other hand does not show temptation when Frodo offers it to him. He closes Frodos hands in his own and forgos his chance to take it. Hes always feared becoming a twisted or oath breaker of a man like Isildor had become. Thats why hes always ran from his destiny. But that fear is what allowed him to become not just Isildors heir but Isildors better because he swept the dishonor from his familys name.