IN THE CRYPT Of the University of Notre Dame’s Sacred Heart Cathedral, under a marble slab in the center aisle, lie the remains of one of America’s most formidable Catholic intellectuals.  More than a hundred years of student footsteps on their way to communion have not yet erased the epitaph. Translated from the Latin it reads: “Here lies Orestes A. Brownson, who came humbly to the recognition of the true faith and devoted his entire life to the valiant defense, by voice and pen, of Church and country.” Part of the Transcendentalist movement that included Emerson and Thoreau, Brownson would upon his conversion to Catholicism devote a lifetime to pressing the special affinity between that ancient faith and the youthful American republic.