As I have shown, throughout his works, Conrad investigates a variety of objects of consciousness: physical objects, human subjects, events, ideas, space, and time. With each object of consciousness, he employs impressionist techniques to show that the epistemological process is individual, and his impressionism consistently leads to human subjectivity as the common element in the appearance of these objects. This common element demonstrates a kind of unity in Conrad's works that may not initially be apparent. Not only is the epistemological experience individual, but it also forms the building block for knowledge of the nature of human existence and the external world, and since objects of consciousness are individual, knowledge is individual as well. Furthermore, the individual nature of the epistemological process also points to questions concerning western civilization of that time, and these questions lead to an uncertainty about what human beings can know.

Conrad specifically emphasizes the uncertainty of knowledge in several instances. The clearest demonstration of this fact occurs when Jim claims that Marlow cannot know what he would have done had he been in Jim's place on the Patna: “You can't tell – nobody can tell” (LJ 92). The uniqueness of the context (physical circumstances and human subjectivity) makes it impossible for others to know how they would respond to a given situation.