Full Idea
Those who know the true use of money, and regulate the measure of wealth according to their needs, live contented with few things.
Gist of Idea
Rational people judge money by needs, and live contented with very little
Source
Baruch de Spinoza (The Ethics [1675], IVApp 29)
Book Reference
Spinoza,Benedict de: 'Ethics', ed/tr. White,WH/Stirling,AH [Wordsworth 2001], p.222
A Reaction
Spinoza himself lived up to this, being incredibly austere in his personal life.