In Victor Hugo's "Les Miserables," the author distinguishes between two mental states: thought and reverie. He suggests that thought represents the diligent work of the intellect, necessitating focus and effort, while reverie serves as a pleasurable distraction that allows the mind to wander freely. This contrast highlights the importance of maintaining a balance between productive thinking and the enjoyment derived from daydreaming.

Hugo warns against substituting thoughtful contemplation with mere reverie, equating this mistake to confusing harmful substances with nourishment. By doing so, he emphasizes the value of critical thinking, suggesting that while reverie can be enjoyable, it should not replace the deeper understanding and insights gained through thoughtful reflection.