Although criminology became its own separate field only in the nineteenth century, we can trace the beginnings of our modern way of thinking about crime to the eighteenth century. The earliest school of thought about crime, now called the classical school of criminology, was a product of the widespread intellectual movement known as the Age of Enlightenment that started late in the seventeenth century in Europe and spread to North America. Here are some of the major Enlightenment ideas that inspired the classical school: people have free will; most behavior is based on the principles of hedonism (behaving in a way that brings pleasure and avoids pain); and everyone in society is entitled to the same basic rights.

The classical school of criminology was not really a theory about the causes of crime like most criminology theories that came after it. Instead, it was a philosophy of human nature, of human society, and governments. Classical school thinkers believed in the basic equality of all people and in ideas of human dignity. As a result, their ideas focused mostly on creating a fair system of laws so that human dignity can be protected.

Cesare Beccaria, who was one of the most influential thinkers from this school, argued that a society needs to have a clear system of laws that would protect individuals from tyrants and from the inconsistent and arbitrary rulings of judges. Beccaria wanted to avoid situations where judges decide cases based on a temporary personal mood or on a quick impression. Beccaria wanted a system of laws that would be a stable guide that all legal authorities can refer to. Laws must be clearly understood by all people and they must apply to all people equally. A due process of law must guarantee that all suspects and offenders receive a fair trial and that their rights will be respected.