The Structure of Shakespeare's Sonnets

KDJ argues that 18-125 "may be seen to constitute, on the Sidneian model, a great central sequence of 108 sonnets." because in 18 "a new and wider perspective is opened [after the narrowness of the The Procreation Sequence]...in which the speaker for the first time expresses his own devotion to the youth and determination to immortalize his beauty in 'eternal lines.'" (100).