I meet architect and educator Ralph Knowles on an unseasonably warm autumn day, even for Southern California. He greets me in shirtsleeves (his shirt is a tropical pattern of vines and branches) and leads me to a seat on the balcony of his condo. The building—a retirement community—is fairly new, but mature oak trees line the quiet street. As we talk about his career, the California oaks form a poignant backdrop. For more than five decades, Knowles, 88, has argued for an architecture that hews closely to nature’s forces and rhythms.