Knaves and fools divide the world.

The saying paints humanity in a bleak two-part division: people are imagined either as knaves, in the older moral sense of dishonest or unscrupulous people, or as fools, who are easily misled. It expresses cynical distrust of the moral and intellectual quality of public life.

It can also serve as a warning that wrongdoing often depends on credulity. The knave gains by manipulation, while the fool enables the scheme through poor judgment; together, these roles seem to account for much of what happens in the world. Its sweeping division is rhetorical, not a fair description of humanity.

Use it as a terse, pessimistic observation when fraud, gullibility, or manipulation appears to explain a situation. Because it harshly and contemptuously labels people in a sweeping way, it suits pointed commentary or literary rhetoric better than a tactful description of particular individuals.