The play opens with Strepsiades, who wakes up in his bed with his son and swears an oath to Zeus. Pheidippides, still sleeping, cries out “that’s unjust!” This reveals that Strepsiades’s son has a sense of justice. We also come to see what is troubling Strepsiades:
He’s going broke because of his son, who loves horses, chariots, and racing;
But also, because he can’t beat his servants to make them obey; he can’t do so because of the war going on, which allows them easily to defect.
Strepsiades is trying to find a way out of this situation, and in thinking about it becomes up with the idea of sending Pheidippides to the thinkery.