In The Heart of Darkness by Joseph Conrad, the author uses a double framing device to enhance the meaning of the central story and specifically to develop his idea of colonialism by developing an image of its duality. Colonialism has a dual nature because it has one form in the country in which the colonial power operates and another at home, and there is a clear difference between the reality and the attitude taken by those who remain back home and who have a romantic idea of colonial life. Marlow is the bridge between the two worlds, and he also has a dual reaction to his own experience. On the one hand, he tries to tell the men on the boat some of the truth, but he lies to Kurtz's intended. He has journeyed to the heart of darkness not only in Africa but within himself, and while he has returned a wiser man, he still maintains some of the romantic notions that fueled the colonial era.
For Conrad, the civilized individual possesses within himself the possibility of the primitive, but society and civilization have created a framework of control by which the individual can escape from that condition. This seems evident in the opening passages as Marlow is about to tell his story to the other men sitting on the deck and refers to the civilizing influence of Western culture from Roman times to the present. The England of two millennia ago, the England to which the Romans came, is compared to the Africa to which Marlow has journeyed. Marlow makes it clear that Africa has a primitive nature, for he describes it as a pre-civilized part of the world. Marlow comments on society at the same time, and to him, society is more an idea than a reality:
The conquest of the earth, which mostly means the taking it away from those who have a different complexion or slightly flatter noses than ourselves, is not a pretty thing when you look into it too much. What redeems it is the idea only. An idea at the back of it; not a sentimental...