I was told that at electrostatic equilibrium, the electric field inside a conductor will be ZERO, so that the charges will not move any more. but why, I argue that, even when the electric field is not zero everywhere inside the conductor, there is still a chance for the charges to be stationary! For example, imagine that, there is a spherical conductor, all the charges of positive are distributed uniformly over the surface. BUT, there is yet a positive charge, somehow placed in the middle of the sphere . All the charges are definitelt stationary in this case, yet the electric field is NOT ZERO inside the conductor! So, isn't that this is a CONTRADICTION to the "fact" that the electric field must be zero inside the conductor? Thanks, Twukwu.