Banquo asks if the witches are dead or alive. He also notes that they seem to be women but they have beards. Macbeth is equally unsure what they are, so he asks. They do not answer this, leaving the suspense in the air. This series of dichotomies is central to the play. These things seem dead and alive, male and female, fair and foul. Macbeth will deal with his own internal conflict of dichotomies as well. The witches proclaim Macbeth as the Thane of Glamis, the Thane of Cawdor, and the future king.
Macbeth's first reaction is fear. Banquo points this out. "Good sir, why do you start, and seem to fear, / Things that do sound so fair," (I.iii.54-55) Macbeth adds that he can not imagine being king, let alone the Thane of Cawdor. When Ross informs Macbeth that he is the new Thane of Cawdor, Macbeth's fear fades a bit, but he is still unsure about the implications of what the witches have said. He says "It cannot be ill, cannot be good." Contemplating this, his fear returns as he considers murder as a route to become king. But then he considers letting things happen on their own. Macbeth is conflicted about these prophecies. Macbeth will continue to battle this inner conflict (fair and foul, ill and good) throughout the play.