You see, César was really, really good on the organ. A master and a skilled improvisor, his love and reverence for the instrument and its sounds was lifelong. Even composing came a distant second to his pursuits on the organ. From 1847 to 1858, he was employed as the organist at Notre Dame de Lorette and then at St. Jean - St. Francois. In 1858, he became the organist at the Basilica of Sainte-Clotilde, where he remained until his death, over three decades later. Alongside his work as a master organist, he taught organ and composition, joining the Conservatoire de Paris faculty in 1872. He was a devoted teacher, beloved and revered by his students (among whom included Vincent d'Indy and Ernest Chausson), whose loyalty to him was fierce. By his fellow teachers, alas, he was merely tolerated, possibly given his Belgian heritage and Germanic leanings musically (Wagner was an influence on his work). He remained much the same through the years, a humble, devout man, deeply committed to his religion, his art, sometimes to the exclusion of the people and sights around him. His own death in 1890, in fact, was likely hastened when he stepped out absentmindedly in front of an oncoming bus on a city street and was hit. (Other accounts argue he was riding a cab that was struck by a horse-drawn trolley.) While he survived -- story has it, he rose, dusted himself off, and continued right on to the lesson he'd been on his way to teach, his health soon deteriorated and he died within the year.

I love this image of him that Bill Parker, in Building a Classical Music Library, creates:

[...] his clothes were ill-fitting, he grimaced to himself as he hurried nervously down the street, he was absent-minded and sometimes embarrassingly childlike. If no one showed up for his classes at the Conservatory, he might stop by Massenet's classroom, pop his head in the door and plaintively ask, "Isn't there anyone for me?" All of this only made him more lovable to his clique of followers. Known as la bande à Franck, they believed in him as a musical prophet, based primarily on his development of "cyclic form," and thought of him as a saintly father.

In the last decade of Franck's life, composition finally burst through him in great profusion--he'd composed only a handful works up to this time, notably for the organ. Unsurprisingly, the new compositions, particularly the Symphony in D minor, seemed created through the lens of his experience as an organist. Timothy Judd, at The Listeners' Club, elaborates on this theory:

The first movement unfolds through a series of sweeping modulations reminiscent of a masterful organ improvisation. In fact, in Franck's hands the orchestra becomes a living, breathing pipe organ. Instruments are mixed and doubled as if a rich array of stops are being negotiated.

You know that term, "pulling out all the stops"? As in, Whoa, Bob really pulled out all the stops for this party, didn't he? Wheee! Its original usage derives from organ-playing. That was what Franck knew how to do, for maximum effect, even without an organ. It explains the astonishing power of the end of Symphony in D minor's already impressive first movement, and much of the final movement. Finally, I get it, after 20 years of listening and wondering!