HATH God, then, given you eyes in vain? Is it in vain that He hath infused into them such a strong and active spirit as to be able to represent the forms of distant objects? What messenger is so quick and diligent? Is it in vain that He hath made the intermediate air so yielding and elastic that the sight penetrates through it? And is it in vain that He hath made the light, without which all the rest would be useless? Man, be not ungrateful; nor, on the other hand, unmindful of your superior advantages; but for sight and hearing, and indeed for life itself, and the supports of it, as fruits, and wine, and oil, be thankful to God: but remember, that He hath given you another thing, superior to them all: which makes use of them, proves them, estimates the value of each.
EPICTETUS. DISCOURSES. Book ii. §23. ¶1.