With health, everything is a source of pleasure; without it, nothing else, whatever it may be, is enjoyable; even the other personal blessings, — a great mind, a happy temperament — are degraded and dwarfed for want of it. So it is really with good reason that, when two people meet, the first thing they do is to inquire after each other’s health, and to express the hope that it is good; for good health is by far the most important element in human happiness.

[Mit ihr wird alles eine Quelle des Genusses: hingegen ist ohne sie kein äußeres Gut, welcher Art es auch sei, genießbar, und selbst die übrigen subjektiven Güter, die Eigenschaften des Geistes, Gemütes, Temperaments, werden durch Kränklichkeit herabgestimmt und sehr verkümmert. Demnach geschieht es nicht ohne Grund, daß man vor allen Dingen sich gegenseitig nach dem Gesundheitszustande befragt und einander sich wohlzubefinden wünscht: denn wirklich ist dieses bei weitem die Hauptsache zum menschlichen Glück.]

Arthur Schopenhauer (1788-1860) German philosopher

Parerga and Paralipomena, Vol. 1, “Aphorisms on the Wisdom of Life [Aphorismen zur Lebensweisheit],” ch. 2 “What a Man Is [Von dem, was einer ist]” (1851) [tr. Saunders (1890)]
    (Source)

(Source (German)). Alternate translation:

In general, however, nine-tenths of our happiness depends on health alone. With it everything becomes a source of pleasure, whereas without it nothing, whatever it may be, can be enjoyed, and even the other subjective blessings, such as mental qualities, disposition, and temperament, are depressed and dwarfed by ill-health. Accordingly, it is not without reason that, when two people meet, they first ask about the state of each other's health and hope that it is good; for this really is for human happiness by far the most important thing.
[tr. Payne (1974)]