Hope, deceitful as she is, serves at least to conduct us through life by an agreeable path.

[L’espérance, toute trompeuse qu’elle est, sert au moins à nous mener à la fin de la vie par un chemin agréable.]

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

Réflexions ou sentences et maximes morales [Reflections; or Sentences and Moral Maxims], ¶168 (1665–1678) [ed. Gowens (1851), ¶171]
    (Source)

Appeared in the 1st (1665) edition. In the manuscript, the maxim read: "L’espérance, toute vaine et fourbe qu’elle est d’ordinaire ..."

(Source (French)). Other translations:

Though Hope be exceeding deceitful, yet it is of this good use to us, that while we are Travelling through this Life, it conducts us an easier and more pleasant Way to our Journey's End.
[tr. Stanhope (1694), ¶169]

Hope, deceitful as it is, carries us agreeably through life.
[pub. Donaldson (1783), ¶223; ed. Lepoittevin-Lacroix (1797), ¶162; ed. Carvill (1835), ¶448]

However deceitful hope may be, yet she carries us on pleasantly to the end of life.
[tr. Bund/Friswell (1871), ¶168]

Our hopes, often though they deceive us, lead us pleasantly along the path of life.
[tr. Heard (1917), ¶169]

Hope, deceitful jade though she be, at least leads us to life's end by pleasant paths.
[tr. FitzGibbon (1957), ¶168]

Hope, utter charlatan though she be, at least lures us to life's end along a pretty road.
[tr. Kronenberger (1959), ¶168]

Hope may be a lying jade, but she does at any rate lead us to the end of our lives along a pleasant path.
[tr. Tancock (1959), ¶168]

Hope, deceitful as it is, serves, at least, to guide us to the end of life by an agreeable path.
[tr. Whichello (2016) ¶168]