Virtue would not go so far if vanity did not keep her company.

[La vertu n’iroit pas si loin si la vanité ne lui tenoit compagnie.]

François VI, duc de La Rochefoucauld (1613-1680) French epigrammatist, memoirist, noble

Réflexions ou sentences et maximes morales [Reflections; or Sentences and Moral Maxims], ¶200 (1665-1678) [tr. Whichello (2016)]
    (Source)

Present in the 1st (1665) edition, with the variant "pas loin" instead of "pas si loin." See ¶169 for related maxims.

(Source (French)). Other translations:

Vertue would not make such Advances, if there were not a little Vanity to bear it Company.
[tr. Stanhope (1694), ¶201]

Virtue would not go so far, if vanity did not bear her company.
[pub. Donaldson (1783), ¶452; ed. Lepoittevin-Lacroix (1797), ¶191]

Worldly virtue would not go far, were vanity not to bear her company.
[ed. Carvill (1835), ¶386]

Virtue would not travel so far if vanity did not keep her company.
[ed. Gowens (1851), ¶209]

Virtue would not go far did not vanity escort her.
[tr. Bund/Friswell (1871), ¶200]

Virtue would be shorter lived, were vanity not its companion.
[tr. Heard (1917), ¶205]

Virtue would not go so far if vanity did not bear her company.
[tr. Stevens (1939), ¶200]

Virtue would not go so far did vanity not keep her company.
[tr. FitzGibbon (1957), ¶200]

Virtue would not go nearly so far if vanity did not keep her company.
[tr. Kronenberger (1959), ¶200]

Virtue would not go so far without vanity to bear it company.
[tr. Tancock (1959), ¶200]