The paper aims to explore James Joyce`s message to the readers in the theme of chances－or coincidences－which he developed in his Ulysses by use of "rhetoric of absence," his narrative strategy of gaps. To carry out that purpose, two representative cases were selected out of the numerous chances which take place in the text; one is the "T/throwaway" motif, the other the "man in macintosh" motif. It is noteworthy that both of these motifs are developed through the method of rhetoric of absence, as termed by Phillip F. Herring, in which Joyce intentionally avoids giving evidence supporting the process of discourses so as to have them appear self-reflexively free of author`s intervention. Upon close examination, it turned out that the former is related to Joyce`s view of language as unstable or arbitrary, and the latter is related with his view of the world as mysterious. Since it is doubtful that Joyce is concerned with chances without any significant reason, it appears that his main and comprehensive concern is to reveal his skeptical vision of life as is exhibited in Stephen`s saying that the world is founded upon the void or incertitude, in expectation that his readers would share his vision.