Quote checked against the text
“The happiness of your life depends upon the quality of your thoughts.” — attributed to Marcus Aurelius
In substance, yes; in this wording, no. The idea is at Meditations, V, 16; George Long’s 1862 edition is quoted below, and the sentence as it circulates is not this translator’s.
In substance, not in these words. Neither “quality of your thoughts” nor “happiness of your life” occurs anywhere in Long’s 1862 translation; the sentence is found only in the lists of quotations that circulate online.
The chapter it comes from is Book V, chapter 16, which opens: “Such as are thy habitual thoughts, such also will be the character of thy mind; for the soul is dyed by the thoughts.” The image is a dye, and the object is the mind, not a life. The word happiness is absent, and the chapter goes on to argue something else entirely: that where a man can live, he can also live well, and that the good of a rational animal is society.
The popular sentence keeps the link between thoughts and their effect and replaces the dyed soul with a promise of happiness. The chapter is in the app with its reference: Meditations, V, 16.
What we searched
Each fragment is searched, normalized, in every file of the editions below. The block is the search and its result, replayed at each build.
The wording was searched in Long 1862 (12 books, 487 chapters) and, in French, Couat 1904 and Barthélemy-Saint-Hilaire 1876 (12 books each).
$ node tools/seo/grep-quote.mjs --lang en --author aurele "quality of your thoughts" "happiness of your life" "dyed by the thoughts"
George Long, 1862 — Meditations · 12 books, 487 chapters (1 file)
"quality of your thoughts" 0 hits
"happiness of your life" 0 hits
"dyed by the thoughts" 1 hit
l. 3673 of thy mind; for the soul is dyed by the thoughts. Dye it then with a
$ node tools/seo/grep-quote.mjs --lang fr --author aurele "qualité de tes pensées" "bonheur de ta vie" "imprégnée de nos représentations"
Auguste Couat, 1904 — Pensées · 12 books, 487 chapters (IV, 19–20 and VII, 47–48 merged by the translator) (12 files)
"qualité de tes pensées" 0 hits
"bonheur de ta vie" 0 hits
"imprégnée de nos représentations" 1 hit
livre-05.txt l. 65 …sera ta pensée même ; notre âme est tout imprégnée de nos représentations sensibles. Plonge-la donc sans cesse dans des idées comme celles-ci : là où l’on peut vivre, on peut bien vivre ; on peut vivre à la cour, donc on peut bien vivre à l…
Jules Barthélemy-Saint-Hilaire, 1876 — Pensées · 12 books, 487 chapters — second French edition, shown beside Couat (12 files)
"qualité de tes pensées" 0 hits
"bonheur de ta vie" 0 hits
"imprégnée de nos représentations" 0 hitsThis sentence appears 3 times in the list of circulating quotes we collected on 2026-08-09.
What the text says
Such as are thy habitual thoughts, such also will be the character of thy mind; for the soul is dyed by the thoughts.
In the app
The passage of this chapter as Stoïque gives it, with its reference.
Your mind takes the character of your habitual thoughts, for thoughts dye the soul.
— MARCUS AURELIUS · MEDITATIONS, V, 16
After G. Long (1862), modernized
How to cite
The idea, not this wording, is at:
Marcus Aurelius, Meditations, V, 16 (trans. George Long, 1862)
Other sentences checked
All sentences attributed to Marcus AureliusAll quote checks
Every passage in Stoïque carries its reference. The 166 passages of Marcus Aurelius are free in the app, each with its book and chapter.