“Things which bestow upon the soul no greatness or confidence or freedom from care are not goods. But riches and health and similar conditions do none of these things; therefore, riches and health are not goods. Things which bestow upon the soul no greatness or confidence or freedom from care, but on the other hand create in it arrogance, vanity, and insolence, are evils. But things which are the gift of Fortune drive us into these evil ways. Therefore these things are not goods.”

Source: 1910s, Proposed Roads To Freedom (1918), Ch. V: Government and Law, p. 75

Source: Guide for the Perplexed (c. 1190), Part III, Ch.10

Letter 2.
Advice to Young Men (1829)

Pt. I, The Unknowable; Ch. I, Religion and Science; quoting from "There is some soul of goodness in things evil / Would men observingly distil it out", William Shakespeare, Henry V, act iv. sc. i
First Principles (1862)

Address at the Conference on Cosmic Design, American Association for the Advancement of Science, Washington, D.C. (April 1999)
This comment is modified in a later article derived from these talks:
:Frederick Douglass told in his Narrative how his condition as a slave became worse when his master underwent a religious conversion that allowed him to justify slavery as the punishment of the children of Ham. Mark Twain described his mother as a genuinely good person, whose soft heart pitied even Satan, but who had no doubt about the legitimacy of slavery, because in years of living in antebellum Missouri she had never heard any sermon opposing slavery, but only countless sermons preaching that slavery was God's will. With or without religion, good people can behave well and bad people can do evil; but for good people to do evil — that takes religion.
:* "A Designer Universe?" at PhysLink.com http://www.physlink.com/Education/essay_weinberg.cfm

II, 11
Meditations (c. 121–180 AD), Book II

I, 8
The City of God (early 400s)
Context: To the divine providence it has seemed good to prepare in the world to come for the righteous good things, which the unrighteous shall not enjoy; and for the wicked evil things, by which the good shall not be tormented. But as for the good things of this life, and its ills, God has willed that these should be common to both; that we might not too eagerly covet the things which wicked men are seen equally to enjoy, nor shrink with an unseemly fear from the ills which even good men often suffer.
There is, too, a very great difference in the purpose served both by those events which we call adverse and those called prosperous. For the good man is neither uplifted with the good things of time, nor broken by its ills; but the wicked man, because he is corrupted by this world’s happiness, feels himself punished by its unhappiness.

Source: Henry V

As quoted in Lives and Opinions of Eminent Philosophers, as translated by Robert Drew Hicks (1925)
Variant translation: The most momentous thing in human life is the art of winning the soul to good or evil.
As quoted in Ionia, a Quest (1954) by Freya Stark, p. 94