res severa verum gaudium
“True joy is a serious thing. ”
(Seneca the younger, Epistulae morales, 23, 4).
This famous sentence is often misinterpreted, as the grammatical subject occupies the secondary position.
It does not say:
“Only a serious thing is real joy.”
Seneca is instructing the younger Lucilius about real joy and how to find it;
“ Hoc ante omnia fac, mi Lucili: disce gaudere. Existimas nunc me detrahere tibi multas voluptates, qui fortuita submoveo, qui spes, dulcissima oblectamenta, devitandas existimo? immo contra nolo tibi umquam deesse laetitiam. Volo illam tibi domi nasci: nascitur, si modo intra te ipsum fit. Ceterae hilaritates non implent pectus; frontem remittunt, leves sunt, nisi forte tu iudicas eum gaudere qui ridet: animus esse debet alacer et fidens et supra omnia erectus.
 Mihi crede, verum gaudium res severa est. An tu existimas quemquam soluto vultu et, ut isti delicati loquuntur, hilariculo mortem contemnere, paupertati domum aperire, voluptates tenere sub freno, meditari dolorum patientiam? Haec qui apud se versat, in magno gaudio est, sed parum blando. In huius gaudii possessione esse te volo: numquam deficiet, cum semel, unde petatur, in veneris.”
[L. Annaei Senecae
ad Lucilium Epistulae XXIII]
“Most of all, dear Lucilius, learn how to rejoice! Do you believe now, i would withdraw fom you all joy, once I forbid the whims of chance and want to see hope, the eversweet seduceress, avoided? On the contrary: was it after me, you never should miss joy! It is my whish that joy should blossom for you at your own home! She does so, once she dwells inside you. Serene emotions of other kind do not go to your heart. They just sooth the crests of sorrow on your forehead and are flighty companions, except you would call it joy when one is laughing: no, for this the spirit must be merry, trustfull and above all things.
Believe me: True joy is a serious thing! Or do you believe a man could with compose – or, as our men of the world prefer saying: serene – countenance despise death, open his house to poverty, rein in his desires and think of enduring pain? He who is able to accomplish all these, is living in deep joy – although it might not seem alluring. In possession of such a joy I want to see you: and it shall never leave you, once you did discover the well, where it does come from.”