Casual use of the phrase in French can be dated back at least as far as
Fénelon in the late 17th century, but it was only brought into literary prominence in the 19th century, first by
Michelet (1857) in his
pantheistic work
Insecte, to contrast the passive life of plants with animal
joie de vivre, and then by
Émile Zola in his
book of that name from 1883–84. in the latter half of the century – a time when its emphasis on enthusiasm, energy and spontaneity gave it a global prominence with the rise of
hippie culture. == Psychology ==