" The exchange of one fear or pleasure or pain for another 

 fear or pleasure or pain, which are measured like coins, the 

 greater with the less, is not the exchange of virtue. O, dear 

 Simnias, is there not one true coin for which all things ought 

 to exchange? and that is wisdom; and only in exchange 

 for this and in company with this is anything truly bought or 

 sold, whether courage or temperance or justice. And is not 

 all true virtue the companion of wisdom, no matter what fears 

 or pleasures or other similar goods or evils may not attend 

 her?" Socrates (in Plato's Phado). 



