There is such a thing as internal collapse. Despairing certitude does not infiltrate a human being without displacing and disrupting certain profound elements that sometimes constitute the man himself. Grief, when it reaches this pitch, routs all strength of conscience. These are deadly crises. Few of us emerge from them true to ourselves and steadfast in our duty. When the limit of endurance is exceeded, the most unshakeable virtue is undermined.

[Il y a des effondrements intérieurs. La pénétration d’une certitude désespérante dans l’homme ne se fait point sans écarter et rompre de certains éléments profonds qui sont quelquefois l’homme lui-même. La douleur, quand elle arrive à ce degré, est un sauve-qui-peut de toutes les forces de la conscience. Ce sont là des crises fatales. Peu d’entre nous en sortent semblables à eux-mêmes et fermes dans le devoir. Quand la limite de la souffrance est débordée, la vertu la plus imperturbable se déconcerte.]

Victor Hugo (1802-1885) French writer

Les Misérables, Part 4 “Saint Denis,” Book 15 “The Rue de L’Homme Armé,” ch. 1 (4.15.1) (1862) [tr. Donougher (2013)]
    (Source)

Valjean "internally collapsing" at the realization that Cosette plans to leave him for Marius, and deciding to track Marius down to confront or even kill him.

(Source (French)). Alternate translations:

There are interior subsoilings. The penetration of a torturing certainty into man does not occur without breaking up and pulverising certain deep elements which are sometimes the man himself. Grief, when it reaches this stage, is a panic of all the forces of the soul. These are fatal crises. Few among us come through them without change, and firm in duty. When the limit of suffering is overpassed, the most imperturbable virtue is disconcerted.
[tr. Wilbour (1862)]

There are such things as internal landslides; the penetration of a desperate certainty into a man is not effected without removing and breaking certain profound elements which are at times the man himself. Grief, when it attains that pitch, is a frantic flight of all the forces of the conscience, and such crises are fatal Few among us emerge from them equal to ourselves and firm in our duty, for when the limit of suffering is exceeded the most imperturbable virtue is disconcerted.
[tr. Wraxall (1862)]

There is such a thing as the sudden giving way of the inward subsoil. A despairing certainty does not make its way into a man without thrusting aside and breaking certain profound elements which, in some cases, are the very man himself. Grief, when it attains this shape, is a headlong flight of all the forces of the conscience. These are fatal crises. Few among us emerge from them still like ourselves and firm in duty. When the limit of endurance is overstepped, the most imperturbable virtue is disconcerted.
[tr. Hapgood (1887)]

There is such a thing as spiritual collapse. The thrust of a desperate certainty into a man cannot occur without the disruption of certain profound elements which are sometimes the man himself. Anguish, when it has reached this stage, becomes a panic-flight of all the powers of conscience. There are mortal crises from which few of us emerge in our right mind, with our sense of duty still intact. When the limit of suffering is overpassed the most impregnable virtue is plunged in disarray.
[tr. Denny (1976)]

There are interior collapses. The penetration of a torturing certainty within man does not occur without breaking up and pulverizing certain deep elements that are sometimes the man himself. Grief, when it reaches this level, is a panic of all the forces of consciousness. These are fatal crises. Few among us come through them unchanged and firm in duty. When the limit of suffering is topped, the most imperturbable virtue is disconcerted.
[tr. Wilbour/Fahnestock/MacAfee (1987)]