Oh shit guys I think I just figured out why myrtlewilson says that Montparnasse is “sad”: it’s because in the first sentence we read about him, he is described (in Hapgood) as a “lugubrious being.”
If that’s the case, we need to talk about the word lugubre. The word (both in French and English; they are of course cognates) comes from the Latin lugubris, meaning “mourning, pertaining to mourning” (lugere means “to mourn”). So right away we’re in the semantic field of death, not just sadness. We’re talking about something that is sad on a cosmic or existential scale, and pretty scary as well. This is not the blues, this is not feeling down in the dumps, this is some really heavy gothic novel shit. Hugo tends to dwell on Bad Stuff and lugubre is a typically Hugolian word for a typically Hugolian topic, along with words like funèbre, sépulcral, blafard, patibulaire, etc.
As such, I would argue that the word lugubre is not being used to describe Montparnasse’s emotions or his temperament; it is being used to describe the phenomenon of Montparnasse. By calling him a “lugubrious being,” Hugo’s not saying he’s a sad person; he’s saying he’s a person who should make you sad—and afraid.
Of course death is sad—for the mourner. But Montparnasse is not the mourner: he’s the corpse. He’s the goddamn “dandy of the sepulcher” (mirliflore du sepulchre); what did I say about lugubre and sépulcral and blafard and patibulaire all going together? Hugo can’t even resist using two of those words in the same paragraph! (Sometimes he uses two of them in the same sentence: “En même temps Thénardier voyait du côté de la Bastille une nuance blafarde blanchir lugubrement le bas du ciel.”)
Death is sad, death is gloomy, death is scary, death is fucking macabre, and Montparnasse is all of those things in the same way. The sadness is intimately tied to all of the other stuff, so if it wouldn’t make sense to say “Montparnasse commits crimes but he feels macabre about it,” it shouldn’t make sense to say he commits crimes but he’s sad about it.
As far as Hugo is concerned, Montparnasse is goddamn supernatural, he’s a zombie and a vampire combined, but the scary thing is that he’s actually a normal flesh-and-blood human being. That is the “boo!” factor, and the tragedy.
ETA: If you want an example of how Hugo actually writes about characters who have been crushed down by society’s bootheel and are actually angry and sad (sad!) about it, look no further than the description of Valjean in Toulon (during his first stint, of course):
N’y a-t-il pas dans toute âme humaine, n’y a-t-il pas dans l’âme de Jean Valjean en particulier, une première étincelle, un élément divin, incorruptible dans ce monde, immortel dans l’autre, que le bien peut développer, attiser, allumer et faire rayonner splendidement, et que le mal ne peut jamais entièrement éteindre ?
Questions graves et obscures, à la dernière desquelles tout physiologiste eût probablement répondu non, et sans hésiter, s’il eût vu à Toulon, aux heures de rêverie, assis, les bras croisés sur la barre de quelque cabestan, le bout de sa chaîne enfoncé dans sa poche pour l’empêcher de traîner, ce galérien morne, sérieux, silencieux et pensif, paria des lois qui regardait l’homme avec colère, damné de la civilisation qui regardait le ciel avec sévérité.
Is there not in every human soul, was there not in the soul of Jean Valjean in particular, a first spark, a divine element, incorruptible in this world, immortal in the other, which good can develop, fan, ignite, and make to glow with splendor, and which evil can never wholly extinguish?
Grave and obscure questions, to the last of which every physiologist would probably have responded no, and that without hesitation, had he beheld at Toulon, during the hours of repose, which were for Jean Valjean hours of revery, this gloomy galley-slave, seated with folded arms upon the bar of some capstan, with the end of his chain thrust into his pocket to prevent its dragging, serious, silent, and thoughtful, a pariah of the laws which regarded the man with wrath, condemned by civilization, and regarding heaven with severity.