Chance is the pseudonym of God when he did not want to sign.

[Le hasard, c’est peut-être le pseudonyme de Dieu quand il ne veut pas signer.]

Théophile Gautier (1811-1872) French poet, writer, critic

La Croix de Berny, Letter 3 (1855) [with Jules Sandeau, Émile de Girardin, and Joseph Méry]

Source (French). Alternate translation:

Let [chance] act, for perhaps it is the pseudonym of God.
[tr. Fendall/Holcomb (1873)]

Frequently misattributed to Anatole France.