The reason we are not often wholly possessed by a single vice, is that we are distracted by several.

[Ce qui nous empêche souvent de nous abandonner à un seul vice est que nous en avons plusieurs.]

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

Réflexions ou sentences et maximes morales [Reflections; or Sentences and Moral Maxims], ¶195 (1665-1678) [pub. Donaldson (1783), ¶442]
    (Source)

Present in 1st (1665) edition. In the manuscript, the ending reads "est que nous en avons plusieurs à la fois."

(Source (French)). Other translations:

The only Reason why we do not give our selves entirely to one Vice, is oftentimes, because our Affections are divided, and we are fond of several.
[tr. Stanhope (1694), ¶196]

The reason we are not often wholly possessed by a single vice, is, that we are distracted by several.
[ed. Lepoittevin-Lacroix (1797), ¶187]

We are not often possessed wholly by a single vice: the reason is, we are distracted by several.
[ed. Carvill (1835), ¶378]

What often prevents our abandoning ourselves to a single vice is, our having more than one.
[ed. Gowens (1851), ¶204]

The reason which often prevents us abandoning a single vice is having so many.
[tr. Bund/Friswell (1871), ¶195]

We are not the victims of a single vice only because we are the victims of so many.
[tr. Heard (1917), ¶200]

We are often saved from exclusive addiction to a single vice by the possession of others.
[tr. Stevens (1939), ¶195]

The multiplicity of our vices often prevents us from abandoning ourselves entirely to one.
[tr. FitzGibbon (1957), ¶195]

What often prevents our being enslaved by a single vice is that we have a number of others.
[tr. Kronenberger (1959), ¶195]

What often prevents our giving ourselves up to a single vice is that we have several.
[tr. Tancock (1959), ¶195]

What often prevents us from giving ourselves up to one single vice, is that we possess several of them.
[tr. Whichello (2016) ¶195]