To name the bigger light, and how the less,That burn by day and night
Early on in the play Shakespeare makes it clear that Caliban has not had the chance to be as educated as some of the other characters. This is important because it shows how easily he could be manipulated to someone else's will. It also plays into the idea that a "monster" or outsider like Caliban is a savage that should be treated as a slave. In fact Prospero calls Caliban a slave in his next line. This ultimately comes back to power binaires and how Prospero is able to control Caliban.