HOW CAN OCCAM"S RAZOR BE USED TO ARGUE STRING THEORY PRO OR CON?

Einstein's Mass-Energy Equivilance (E=MC^2) is a good example of this. E=MC^2 is a simple equation which sums up that energy and mass are equal and transmutable.

The M-branch of, String theory is multi dimensional, cumbersome and just plain ugly. Is it really necessary for String theory to incorporate all those dimensions? Isn't there a simpler way to explain a unifing theory than vibrating forces from other dimensions? Especially since we don't really comprehend the gravity force...

William of Occam would be impressed and perhaps amazed at his formalization of the rule of parsimony (keep it simple, stupid!) being applied to cutting edge physics.

And the simple answer is that it cant.