"In later years when Mies was enjoying his greatest fame in America, he was known as the silent Mies, profound and taciturn, who expressed himself in works rather than in words. "build, don’t talk", was the charge his admiring students often attributed to him. The image is quite at odds with what we have written of his active and skillful politicking within the profession in Germany during the mid-1920s. Yet consistent with his biography, he was slow to build, more precisely, a long time in seeing his modern ideology realized in modern work. During and for several years after the period of the five projects, indeed after his historic labors at the Weissenhofsiedlung in Stuttgart in 1927, notably more of his designs were unbuilt than built. And among those that were constructed, several were so traditional in manner, so much nearer his prewar work than the five projects, that by 1925 it could be said of him that he talked substantially more modern architecture than he made."
Franz Schulze, Mies Van Der Rohe: A Critical Biography, "Europe out of the Ashes" University of Chicago Press, Chicago, 1995, page 120.