“We never see the true state of our condition till it is illustrated to us by its contraries, nor know how to value what we enjoy, but by the want of it.”
Source: Robinson Crusoe (1719), Ch. 10, Tames Goats.
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Daniel Defoe 43
English trader, writer and journalist 1660–1731Related quotes

Source: Teaching Critical Thinking: Practical Wisdom

… It is not to be assumed that we offer for sale articles required for our own consumption. … We wish to part with a useless thing, in order to get one that we need; we want to give less for more. … It was natural to think that, in an exchange, value was given for value, whenever each of the articles exchanged was of equal value with the same quantity of gold. … But there is another point to be considered in our calculation. The question is, whether we both exchange something superfluous for something necessary.
Le Commerce et le Gouvernement (1776), as quoted in Marx's Capital, Vol. I, Ch. 5.

an epithet characteristic of the silver age of Hebrew literature and of our Anglican Prayer Book, but never once used as an epithet of God by Him who knew Him as He is. By way of compensation, we must lay far more stress on "Wise" and "Good."
Paradosis : Or "In the Night in Which He Was (?) Betrayed" (1904), "Introduction : Paradosis or Delivering Up the Soul", p. 7

“Till we know that, what is all our knowledge; how shall we even so much as "detect?”
For the vulpine sharpness, which considers itself to be knowledge, and "detects" in that fashion, is far mistaken. Dupes indeed are many: but, of all dupes, there is none so fatally situated as he who lives in undue terror of being duped.
1840s, Heroes and Hero-Worship (1840), The Hero As King

“Let us greedily enjoy our friends, because we do not know how long this privilege will be ours.”
Epistulae Morales ad Lucilium (Moral Letters to Lucilius), Letter LXIII