Free cultures are cultures that leave a great deal open for others to build upon; unfree, or permission, cultures leave much less. Ours was a free culture. It is becoming much less so.
Leaving a culture open leaves more room for people to build upon other's ideas. But at the same times gives more people the opportunity to copy other peoples work. A unfree culture leaves it harder for others to build off of other peoples ideas. We are becoming a more unfree culture with copy right laws.