Plutarch De Cupiditate Divitiarum 10

[10] The happiness riches pretend to is such that it depends upon spectators and witnesses; else it would signify nothing at all. But it is quite otherwise when we consider temperance or philosophy, or such knowledge of the Gods as is requisite. For these, though unknown to all other mortals, communicate a peculiar light and great splendor within the soul, and cause a joy that dwells with it as an inmate, whilst it enjoys the chiefest good, though neither Gods nor men may be privy to it. Such a thing is truth, virtue, or the beauty of geometrical and astrological sciences; and do riches, with their bravery and necklaces and all that gaudery that pleases girls, deserve to be compared with any of these? When nobody observes and looks on, riches are truly blind and deprived of light. For if a rich man makes a meal with his wife or familiars alone, he makes no stir about magnificent tables to eat on or golden cups to drink in, but uses those that come next to hand; and his wife, without any gold or purple to adorn her, presents herself in a plain dress. But when he makes a feast,—that is, when the pomp and theatre is to be fitted and prepared, and the scene of riches is to enter,— then they provide lamps, and much ado is made about the drinking-cups, they put the cup-bearers into a new dress, they bring forth whatever is made of gold and silver or set with precious stones, thus plainly declaring that they would be looked upon by all for rich men. But even though he should eat his meal alone, he wants hilarity of mind and that contentment which alone makes a feast.