In The Adventures of Huckleberry Finn, how do the raft and the shore symbolize civilization and freedom, respectively? What does Twain's message about civilization seem to be? Is he cynical about what civilization has brought to America?
In Mark Twain's novel The Adventures of Huckleberry Finn, there are surprisingly few symbols. However, as you noted, the raft and shore are both symbolic of freedom and civilization, respectively.
Whenever Huck and Jim are on the raft, they are literally and figuratively free from civilization. They do not belong to any township and can go wherever the river takes them. They also do not follow society's rules, such as wearing clothing or the segregation and hierarchy of race in the setting of the book. Whenever Huck and Jim land on shore, they are forced to reclaim these practices that they have discarded, the most influential of which is their relationship as a white boy and a black man. Therefore, the shore represents their return to civilization.
The construction of the book defines this return as the opposite of the raft and therefore of freedom, lending it a negative connotation. Twain's social commentary on the time and place in which the novel's events take place is subtle, laced with humour, but unmistakeable. He believes that many elements of civilization, including the aforementioned racism but also practices such as didactic religion and mass swindling, are inseparable from civilization as it existed when he wrote his novel. Huck and Jim, presented as a counterpoint to civilization, prove that Twain still maintains a degree of hope for the civilization overcoming these negative aspects.