Great perils have this beauty, that they bring to light the fraternity of strangers.

[Les grands périls ont cela de beau qu’ils mettent en lumière la fraternité des inconnus.]

Victor Hugo (1802-1885) French writer

Les Misérables, Part 4 “Saint Denis,” Book 12 “Corinth,” ch. 4 (4.12.4) (1862) [tr. Wilbour (1862)]
    (Source)

On the varied Parisians working together at building the barricades.

(Source (French)). Alternate translations:

Great dangers have this beauty about them, that they throw light on the fraternity of strangers.
[tr. Wraxall (1862)]

Great perils have this fine characteristic, that they bring to light the fraternity of strangers.
[tr. Hapgood (1887)]

It is the ennobling quality of danger that it brings to light the fraternity of strangers.
[tr. Denny (1976)]

Great perils share this beauty, that they bring to light the fraternity of strangers.
[tr. Wilbour/Fahnestock/MacAfee (1987)]

That is the beauty of great danger, it brings out the fraternity of strangers.
[tr. Donougher (2013)]