On the island of reason all people are reasonable. As the sage Blectrue, advisor to the governor of the island, explains to newcomers, it is women who pay court to the men. When individuals who are not reasonable land there, they lose their size in proportion to their degree of madness. Eight French land in this island: a courtier, his gascon secretary, named Frontignac, a countess and her maid Spinette, a poet, a philosopher, a doctor and a farmer.
In their capacity as French, these characters have become dwarfs on arrival, but they are so in various degrees. One whose size is less affected by Blaise is the peasant, and therefore, he is the most reasonable. Blaise agrees frankly that he often overstepped the rules of temperance, and he often wanted to deceive the purchasers of his products. As he admits his mistakes and takes the resolution to correct them, he grows up in the eyes of his companions.