Pleasures may be based on illusion; happiness must be based on truth.

[Le plaisir peut s’appuyer sur l’illusion; mais le bonheur repose sur la vérité.]

Nicolas Chamfort (1741-1794) French writer, epigrammist (b. Nicolas-Sébastien Roch)

Products of Perfected Civilization [Produits de la Civilisation Perfectionée], Part 1 “Maxims and Thoughts [Maximes et Pensées],” ch. 2, ¶ 153 (1795) [tr. Parmée (2003), ¶ 123]
    (Source)

(Source (French)). Alternate translations:

Pleasure may rest upon illusion, but felicity must repose upon truth.
[tr. Mathers (1926), # 153]

Pleasure may be be based on illusion, but happiness rests on truth.
[tr. Merwin (1969)]

Pleasure can be based on illusion, but happiness is founded on truth.
[tr. Pearson (1973)]

Pleasure may be based on illusion, but happiness rests on truth.
[tr. Epstein (1991)]

Variants:

• "Pleasure can be supported by an illusion; but happiness rests upon truth."
• "Pleasure may come from illusion, but happiness can come only of reality."