A novel theory of plasmas is proposed as an alternative to the usual MHD description. The basic element of Fiber Theory is a filamentary line current in the plasma, in contrast to a magnetic field line in the usual MHD model. Self-organization of the fibers leads to an explanation of observed helical current formation and field-reversal. Natural and driven oscillations of the fibers reproduce many features of what have been traditionally interpreted as instabilities. Basic tokamak operation is better understood via the picture afforded by the fibers. Suggestions for improved tokamak operation are given.