I know the two phrases have been adopted into the English lexicon, but raison d'etre and joie de vivre are phrases, not words. As phrases they certainly sound better in French than would their literal translation to English. Are there any 'more English' words or expressions for the same concepts? If not, doesn't that seem odd, or is it common enough for even borrowed phrases to supplant the development of a native term? (Further, it seems a little conspicuous that a language would lack native terms for such core concepts of the human experience!).
Output: We can trace most English words back to a time they were borrowed from another language: Image from Wikipedia.org The expressions raison d'etre and joie de vivre, are relatively recent, acquisitions: raison d'etre (n.) 'excuse for being,' 1864, first recorded in letter of J.S. Mill, from French raison d'etre, literally 'rational grounds for existence.' joie de vivre (n.) 1889, French, literally 'joy of living.' etymonline.com emphasis added I might add that the acquisition of joie de vivre seems incomplete, as the etymology lists it as French, rather than from French. It seems to have a reasonable chance of making a complete entry into English eventually, since we have always been quite hospitable toward elegant French expressions. I still italicize joie de vivre as a foreign expression in my writing, but it seems common enough that some might consider it pure English. As a reasonable intersection of the two French phrases, I like life force: noun The vital principle or animating force within living beings: The American Heritage® Roget's Thesaurus. The rational basis of our existence as living things is some life force that we do not yet fully understand, and joy seems to be a particularly meaningful expression of our life force. Some may complain that the word force is still too French, because it was borrowed from Old French, but it was actually quite a long time ago: c. 1300, 'physical strength,' from Old French force 'force, strength; courage, fortitude; violence, power, compulsion' (12c.), from Vulgar Latin *fortia (source also of Old Spanish forzo, Spanish fuerza, Italian forza), noun use of neuter plural of Latin fortis 'strong, mighty; firm, steadfast; brave, bold' (see fort). etymonline.com emphasis added If we concede to the objections against force, we can still be satisfied with plain old life, which is about as English as any English word can get: Old English life (dative lif) 'existence, lifetime, way of life, condition of being a living thing, opposite of death,' from Proto-Germanic *libam (cognates: Old Norse lif 'life, body,' Dutch lijf 'body,' Old High German lib 'life,' German Leib 'body'), properly 'continuance, perseverance,' from PIE *leip- 'to remain, persevere, continue; stick, adhere' (see leave (v.)). Much of the modern range of meanings was present in Old English. Meaning 'property which distinguishes living from non-living matter' is from 1560s. Sense of 'vitality, energy' is from 1580s. Extended 1703 to 'term of duration (of inanimate objects).' etymonline.com emphasis added Language is my life. Meaning: Language is my conscious rationale to work another day, and the deepest joy of my heart.