The Nature of a Promise: Topic of Choice

.."and Ransom, who had already wasted some time in exploring it, would certainly have turned away if he had not been bound by his unfortunate promise to the old woman” (Lewis 11)

Reading this, made me think about the nature of a promise. In the first chapter of Out of the Silent Planet, Ransom is wandering along in search of a place to stay and runs into a woman in dire need of finding her son. Ransom caught up in this unfortunate situation, gives his word to this woman. Though this promise that he makes is no doubt driven by his desire to find a place to stay, he agrees to her call for help. Can a promise ever be truly authentic? Ransom is in need of a place to stay, so it appears that his promise is more selfish and not solely out of good intention. As we know, Ransom's promise leads him to be kidnapped.