“But if we have recognized that pain as such is inevitable and essential to life, and that nothing depends on chance but its mere fashion, the form under which it presents itself, that thus our sorrow, present, fills a place that without it would at once be occupied by another which now is excluded by it, and that therefore fate can affect us little in what is essential. Such a reflection, if it were to become a living conviction, might produce a considerable degree of stoical equanimity and very much lessen the anxious care of our own well-being.”
The World as Will and Idea
Fourth Book. The World as Will. Second Aspect. Section 56-57