How does the first half of Macbeth's soliloquy contrast with the second half in Act II??Act II scene I

MacBeth's soliloquy is divided in two ways: his perception of time, his conflict with conscience and fate. 

First of all, regarding time, one critic states that there are three times in "MacBeth":  chronological, providential, and MacBeth's time in which he cannot distinguish past, present, or future time.  In his soliloquy, MacBeth exemplfies this confusion.  At first he foresees the bloody dagger that he will use to kill Duncan. (II,ii,33-49).  Then, "wicked dreams abuse...(II,I,50).  MacBeth returns to the past as he recalls wolves, ghosts, Hecate, horror, and footsteps (II,ii,50-59) and remembers that "witchcraft celebrates II,ii,50).  At the end of the soliloquy, the inner workings reflect on the near future: 

...the bell invites me/Hear it not, Duncan, for it is a knell/That summons thee to heaven, or to hell

Secondly, in the beginning of MacBeth's soliloquy, he states that vision of the dagger leads him ("marshal'st me," l.42), but later in the speech, MacBeth says that the bell "invites me" (l.62).  So, although at first MacBeth feels the influence of the future and the past, he chooses his actions in the present: "I go, and it is done....(II,ii,62).  MacBeth's emotional state is revealed in this soliloquy; he is tossed between his conscience as he questions what he sees and his acceptance of fate as he alludes to magic and witchcraft and the bell that summons him.