His mind has been enslaved and repressed for so long that it affected his view of life and his memory. Where John and Annie might have memories, which are associated with the fine weather and smooth breezes, Uncle Julius will always be affected by his enslavement. As James says, anything that emerges in the brain is first required to be introduced and then when it is introduced, it is introduced as the correlate of something that already exists. For John and Annie, these kinds of memories (of slavery) were never introduced and therefore they never existed because they never lived as slaves; they only heard about slavery, they never experienced it.
John and Annie were incapable of recalling memories such as the story of Daves Neckliss, but after the heard Uncle Julius recollection of the incident it seemed as if it now too became a part of there memories. James states that we can remember something because of our associations because of our organized brain-paths. I think that James means that if we listen to a story or someone recalling a previous memory that in a way it also becomes a part of our memory through association.
Chapter 12 on The Self by, William James
Daves Neckliss by, Charles W. Chesnutt View More »