Stobaeus on Stoic Ethics 19

Of good things, some are final, some are instrumental, and some are both. 

For the prudent man and one’s friend are only instrumental goods, but joy and good spirits and confidence and prudent walking are only final goods; all the virtues are both instrumental and final goods since they both produce happiness and fulfill it, becoming parts of it. 

Analogously, of bad things some are instrumental to unhappiness, some are final, and some are both. 

For the imprudent man and one’s enemy are only instrumental bad things, but pain and fear and theft and imprudent questioning and similar things are only final bad things; the vices are both instrumental and final bad things since they produce unhappiness and fulfill it, becoming parts of it. 

IMAGE: Rebecca Dulcibella Orpen, The Philosopher's Morning Walk (c. 1880)