Follow where reason leads...

The love episode of Dido and Aeneas is an important one in the Aeneid because the main force pulling Aeneas out of the relationship is his duty to found Rome. This force is embedded in ancient Rome’s influence from Greek Stoic philosophy. The ancient meaning of the stoics stresses the rule "follow where reason leads.” And this is what Aeneas does when he decides not to pursue his love for Dido and instead leave. In this case, Aeneas gives up a chance at a new love and also causes Dido to suffer. If Aeneas were to surrender his love to Dido, then he would not meet his goal or ,in this case, his destiny. By subduing his true emotions, Aeneas is exemplifying the stoic hero.

Later, we find that Aeneas will marry a woman he does not love, but he will marry her becasuse it is will serve the plan.

Reference: http://en.wikipedia.org/wiki/Stoics