...be  skeptical, but  not  cynical...

p/s... A skeptic says "give me reason to believe".

         A cynic says, "there is no reason to believe." 

Well, we can't progress from a premise of "nothing is true and nothing worthwhile." ...but a skeptic can assume reality exists and operates according to certain principles (what better premises do we have?)...and even if we live in a world of temporary beliefs and "probable truth," we have the possibility of knowledge and creativity.