Ulysses is famous of course for introducing stream of consciousness to fiction. Characters' thoughts, fragments of memory and fantasies are mixed with input from the outside world. But it is all rather academic for me. Despite Joyce's attempts to replicate the flow of sensation through characters' minds with a diverse repertoire of literary effects, I doubt anyone has such intelligible thought processes as the characters in Ulysses do. In my own experience, vast stretches of mental time are passed without any thoughts that are expressed internally in words. This is a failing of the stream-of-consciousness method. An author must either include blank pages, pages of scribbling, musical notes, etc., or give up the pretence that one is reproducing the mental process. An author has to acknowledge that out of the nearly infinite range of daily human experience he is selecting specific items to put together artificially to represent through language what is largely inarticulate.
The stream-of-consciousness approach introduced by Joyce has had a great effect on modern writing, but Ulysses may be the over-the-top experiment (we won't even mention Finnegans Wake) that has allowed other writers to use the technique selectively as is appropriate in their writing. read the complete article here