William of Ockham

The will is free and not determined by the intellect.

Simplicity is the hallmark of truth.

Words signify concepts, and concepts signify things.

There are no real universals in the world, only particulars.

Faith and reason are distinct paths to truth.

The essence of a thing is known through its effects.

Do not assume more causes than are necessary to explain the effect.

Cognition arises from the interaction of mind and world.

The soul is the form of the body, nothing more.

Truth is simple; error is complex.

Nominalism frees the mind from unnecessary abstractions.

Every proposition is either true or false.

God wills freely, without compulsion.

The shortest path to knowledge is direct observation.

Concepts are signs, not substances.

In theology, as in logic, simplicity prevails.

The mind knows individuals, not genera.

Avoid multiplying miracles without need.

Logic is the art of reasoning well.

Existence precedes essence in creation.