In civil society, property and person count through the law. So whoever commits a crime there does not only harm one single person. He harms the universal thing.

What follows from this?

Now it also counts how dangerous a deed is for society. On the one hand, this makes the crime bigger. On the other hand, a firm society is sure of itself. A single thief does not shake it. So it can punish more mildly.

A contradiction?

Only on the surface. A shaky society must punish harshly. It must set an example against the example of the crime. A firm society does not need this. For it, the crime is something isolated.

The measure changes:

How dangerous a deed is depends on the condition of society. Here lies the justification for punishing the theft of a few pennies or of a turnip with death. And it also justifies a mild punishment for a theft a hundred times bigger. So harsh punishments are not unjust in themselves. They fit their time.

A look back:

In the old tragedies, kings murder one another. The citizens do not feel harmed by this. In civil society, it is different. There, a crime hits everyone.

Summary: In society, the danger of a deed also counts. So a firm society can punish more mildly. Every penal code belongs to its time.