The story explores a different set of ideas, from the simple psychological evaluation of two opposing characters, through to the widespread issue of colonialism. On the surface level, the story is mostly a characterization of Walker, the perfect colonial ruler. Not all of Walker’s traits are negative, he likes to keep fairness, and doesn’t take advantage of the natives for personal monetary gain. Instead, he sees himself as a fatherly figure, mentally above the natives (whom he undermines by calling them children) and likes to drink and take advantage of his power over the opposite sex.
Mackintosh is a character critic; he observes and criticizes Walker and feeds his ever-growing hatred for the boastful man. The two are complete opposite, Walker doesn’t take himself or life seriously, he is loud and obnoxious while Mackintosh is quiet and reserved and secretly broods on every joke and every response he makes.
The story portrays the problem of colonialism. Here we have a white man, a white knight who came to modernize and educated the poor, and ignorant natives of the Samoan islands, enforcing respect for his ways while disrespecting their boundaries, intelligence and tradition.
The ending of the story might seem unexpected and hopeless, but, taking into account the sensitive characteristics of Mackintosh, he is too aware of the wrongs of the system to be a representative of it on the island, it isn’t so surprising.