Since this is such a complex question, we'll focus in on a theme or two from each of these sections. We'll start with lines 1112–22, in which Arcite sees Emelye for the first time and falls in love with her. We can identify the themes of love at first sight and the physical and emotional pain caused by separation from one's beloved.
In lines 1153–76, Arcite tells Palamon that even though he saw Emelye after Palamon did, he actually loved her first because Palamon didn't know if she was a goddess or a mortal woman. His love, therefore, is for divinity, but Arcite's is for a human creature. These lines reveal how someone can twist his “reason” to come up with an explanation to fit his desires.
Lines 1251–67 show Arcite speaking of God's providence, one of the tale's major themes, and proclaiming that people do not know how to best choose for themselves. In fact, they are like drunken men who know they have a house but cannot find it. Therefore, they must rely on God's better judgment.
In lines 1785–1810, Theseus discourses on the strong, and often destructive, power of love, for Arcite and Palamon are wounding each other sorely as they fight over Emelye. We may wonder how much “love” is actually involved here when these two friends and kinsmen have turned into enemies for the sake of a woman who doesn't even know them.
Lines 1936–54 describe the interior of Venus's temple. The images on the walls show people in misery, for wisdom, riches, beauty, hijinks, strength, and hardiness have no influence over the erotic love Venus represents. Such love drains people of all of these and makes them wretched.
In lines 2304–25, Emelye, who is about to become the prize in the upcoming tournament, prays to Diana that the goddess may turn the hearts of Arcite and Palamon away from her. If she must have one of them, however, she prays for the one who desires her most. Emelye expresses the near despair of a woman caught up in the games and plans of others with no choice in the matter. She is certainly the most ill used character in the tale, for no one pays attention to her preferences. She does not want to marry either man but longs to remain single and free.
Lines 3041–56 offer a moral from Theseus: it is best to die at the height of one's honor when one's good name is sure to be preserved. This is, of course, small comfort to the person dying or to his loved ones, but Theseus is trying to make the best out of the situation, and in doing so, he reveals the prime position of honor.
Finally, in lines 3090–3108, the tale draws to its conclusion. Palamon marries Emelye, who has gotten over her resistance and has fallen in love with him, which goes to show that even the most complicated of stories can turn out well in the end.