Answer:
You use a knife to slice my head. And weep beside me when I am dead.
What is the freedom of birds and the pen of old men?
Dies half its life. Lives the rest. Dances without music. Breathes without breath.
Neither bought nor sold but more valuable than gold. It is built but not by hand. What is it?
I build up castles. I tear down mountains. I make some men blind. I help others to see.
I have two eyes in the front and a lot of eyes on my tail