Actually, metaphysics is a branch of philosophy investigating the fundamental nature of being and the world of beings.  It "goes beyond physics" because Aristotle treated being after physical science in his writings, and simply labeled the latter "after the physics," or in Greek "meta ta physica." To say that metaphysics is "located solely in the intellect" is simply untrue as well as misleading in many ways!  And if it's the link between faith and reason you're looking to explore, you might get more traction out of (Franciscan) St. Bonaventure than from (Dominican) Thomas Aquinas!