William of Ockham

The rights of individuals are paramount.

Freedom of conscience is essential.

The power of the ruler is for the good of the ruled.

Tyranny is to be resisted.

The common good is the highest law.

All knowledge begins with experience.

Concepts are signs, not things.

Logic is concerned with terms and propositions, not with things themselves.

The principle of parsimony is a guide to truth, not a guarantee.

I am a Catholic, but not a Romanist.

Entities should not be multiplied beyond necessity.

Pluralitas non est ponenda sine necessitate.

What can be done with fewer assumptions is done in vain with more.

Nature is the source of all true knowledge.

Universals are fictions of the mind.

No sign leads to the understanding of its object except in virtue of some other sign.

The truth of propositions is not in the things themselves.

Intuitive cognition is of the existent; abstractive cognition of the nonexistent.

God can make all things possible, but He does nothing without reason.

Knowledge comes through the senses, not through innate ideas.