“These men and Christians cannot know what slavery is; if they did, such a question could never be open for discussion. And from this arose a desire to exhibit it in a living dramatic reality. She has endeavored to show it fairly, in its best and its worst phases. In its best aspect, she has, perhaps, been successful; but, oh! who shall say what yet remains untold in that valley and shadow of death, that lies the other side?”

Uncle Tom's Cabin (1852), Concluding Remarks
Context: The author hopes she has done justice to that nobility, generosity, and humanity, which in many cases characterize individuals at the South. Such instances save us from utter despair of our kind. But, she asks any person, who knows the world, are such characters common, anywhere?
For many years of her life, the author avoided all reading upon or allusion to the subject of slavery, considering it as too painful to be inquired into, and one which advancing light and civilization would certainly live down. But, since the legislative act of 1850, when she heard, with perfect surprise and consternation, Christian and humane people actually recommending the remanding escaped fugitives into slavery, as a duty binding on good citizens, — when she heard, on all hands, from kind, compassionate and estimable people, in the free states of the North, deliberations and discussions as to what Christian duty could be on this head, — she could only think, These men and Christians cannot know what slavery is; if they did, such a question could never be open for discussion. And from this arose a desire to exhibit it in a living dramatic reality. She has endeavored to show it fairly, in its best and its worst phases. In its best aspect, she has, perhaps, been successful; but, oh! who shall say what yet remains untold in that valley and shadow of death, that lies the other side?