Love conquers all! Harry's greatest power is not his ability to excel at Defense Against the Dark Arts. His greatest attribute is not his courage. We learn in Harry Potter and the Half-Blood Prince that Harry's greatest power lies in his ability to love. Even though he's had a rough childhood, even though he's known suffering, he is still able to love and empathize with those around him. He makes the choice to love and to act out of love at all costs. Love is the antidote to Voldemort's Dark Magic, for his magic does not know love's power.