Marlow Says that he detests lies. Why does he dislike lies? Does this implied preference for the truth hold constant in the novella?

Marlow states that, "You know I hate, detest, and can't bear a lie, not because I am straighter than the rest of us, but simply because it appalls me." There is moral ambiguity with Marlow. He likes to separate himself from the lies and deceit of Europeans yet he comes pretty close to lying to the brick maker by letting him think he (Marlow) is influential. By the end of the novel, marlow concedes that he is not a beacon of truth and has in fact become "as much of a pretense as the rest of the bewitched pilgrims."