A detailed experimental study of the bootstrap and Pfirsch–Schlu¨ter currents that are predicted by neoclassical transport theory is presented. In a toroidal octupole, on magnetic surfaces within the separatrix, the observed parallel plasma currents are in excellent quantitative agreement with neoclassical theory with regard to the spatial structure (along a magnetic surface), collisionality dependence, and toroidal magnetic field dependence. On magnetic surfaces outside the separatrix, the ion portion of the parallel current is in agreement with neoclassical theory, but the electron parallel current is observed to obtain a unidirectional component that deviates from and exceeds the theoretical prediction.