Merchant of Venice and Bonds

"The ancient saying is no heresy
Hanging and wiving go by destiny"

During our discussion about bonds in the context of Merchant of Venice, there was this one quote that stuck out in my mind's eye. This was never really a topic that was broached during our discussion, but something that appears quite prevalently in the works of Shakespeare that I have come into contact with. The idea that we are all bond to our pre-determined destiny. Our actions and decisions have been pre-formed prior to our conception and placement upon the face of this planet. The old debate between free will and destiny rears its ugly head yet again. Are the characters of this play really free to make their decisions, choose their own fate? Are any of us in fact free to follow our own paths? Are we instead just actors, with cast roles set upon a stage for the mere entertainment of another force? These questions are not as easy to answer as would first appear. If we are in fact, in nature these characters, would our roles perhaps supersede any potential understanding outside of the knowledge it takes to play our pre-determined roles? The answer is either yes or no, of course depending our your particular role in our predetermined story.