Chapter 6 studies the Josephson tunneling effect in a superconductor-insulator-superconductor junction. The d-wave energy gap gives rise to a geometry dependent phase factor in the tunneling current. This leads to a unique phase-sensitive tool for experimentally detecting the d-wave pairing symmetry through a corner-sharing or tri-crystal junction. It is this kind of measurement that yields the strongest evidence for identifying the pairing symmetry in cuprate superconductors. The paramagnetic Meissner effect is discussed at the end of the chapter.