Abstract: Through ancient Stoic philosophy we analyze the emotions and the plausible imperialist actions of the fictional characters Charles Marlow and Kurtz from the novel Heart of Darkness (1899) by Joseph Conrad. Based on Stoic epistemology/psychology, we explain what correct emotions are, and what incorrect emotions or passions, páthē, are, with this we will show the actions of Marlow and Kurtz. We propose that the páthē pushed the perpetration of what we will call a “vicious katabasis” or vicious travel to the center of Africa. We will establish that this katabasis is a product of the European imperialism-capitalism and the passions-vices which, in turn, have as cause an epistemological error-unknowledge about what is the true “Good”.