For architects and for architectural historians, critical lessons reside in the tangible. In examining the transition from the Roman basilica to the domed Byzantine cathedral, we literally see and can trace the intellectual, political, and philosophical transitions of empire; a telling detail, like Proust’s taste of a petite Madeleine soaked in tea, can unlock a world of memory.

Pasadena, California, encompasses such a tectonic shift, visible not in the seismic record, but in two buildings. Each represents a distinctive moment in architectural history, summing up the motives of generations of designers, thinkers, and makers. Each lies within blocks of the other. Each asserts a radically opposed worldview, poised on opposite shoals of World War I—asserting an identity visibly, even tangibly, in its personal fabric and structure. A consideration of the two offers an essay on the quintessential differences between genius and craft, prompting us to consider them together.

The David and Mary Gamble House (1908), by Charles Sumner and Henry Mather Greene, represents a culmination, a hyper-refinement, of American domestic design. Set on the brow of Westmoreland Place, a residential street near Pasadena’s Brookside Park, the Japanese-inflected Gamble House inculcates the traditions of the craft of wood joinery and of refinement in material and aesthetic choice that had evolved with the American house. For subsequent generations, the images of interlocking, rhythmic balusters along the steps counterpoised against naturalistic stained-glass windows have defined a kind of stylistic perfection.

Down the hill, however, on a challenging lot on Prospect Circle, a new world emerges. Frank Lloyd Wright’s house for Mrs. G.M. Millard, called La Miniatura (1923), smolders with near-palpable energy, an essay in an entirely new language. Its name deceives. While it may be small, this, the first of Wright’s textile block houses in Los Angeles, rises from a conceptually original system in which the architect interlaced patterned modular concrete units into a three-dimensional, cubic construction that modeled space in unfamiliar, transcendent ways. Compared to the Gamble House, we have jumped through the looking glass.

How do they differ? Whereas the Gamble House crowns a hill in a conventional way, open to Mrs. Gamble’s beloved rose garden and directly visible to the street, La Miniatura nestles into a hitherto unbuildable lot, transformed into a naturalistic Eden. The floor plan and the sections at the Gamble House follow familiar room arrangements, from the central hall to the artful arrangement of living, dining, and servant spaces. At the Millard House, plan and section are indissolubly related, in which low passageways or places for human intimacy explode into heroic living spaces. Power seems contained, locked up, in the material, while the Gamble House allows space to bleed through artful portals.

Both are characterized by their peculiar reactions to California light and air. Up the hill, the Greene brothers allowed a bidirectional flow, inviting prescribed axial encounters with street and garden; the formality inheres in the geometry. At La Miniatura, as critic Martin Filler has asserted, chiaroscuro compounds the effect. Light and shadow create a near-symphonic interplay, both within the building and outside in the ravine garden, animating the spatial composition and filtering across the structural fabric of the house. In describing his method of building, Wright referred to his own craft in the textile as “weaving,” or as historian William Allin Storrer asserts, “knitting” together concrete and steel.

While generations of students of architecture have cut their teeth on the gorgeous imagery that surrounds both buildings, pouring over picture books and, later, Web sites, one fundamental truth emerges: No two-dimensional representation can capture the essence of either project. Compared on the printed page, both seem equally compelling, though differentiated by architectural language. In one brief encounter on a day in Pasadena, California, however, the 20th century speaks eloquently. For those few able to inhabit these structures, no choice is demanded: Through them you can hear a century speak.