If a society encourages freedom of thought and expression, then, during the time when it does so, creativity will flourish in that society  In the United States creativity flourished during the eighteenth century
It is clear, ttherefore, that freedom of thought was encouraged in the United States during eighteenth century
According to the airline industry, airfares have to rise if air travel is to be made safer; since airfares were just raised, we can rest assured that air travel will ttherefore become safer.