The Republic

 is a book found in Deus Ex: Invisible War. It is an excerpt from a longer work of the same name by Greek philosopher.

Transcript
The Republic by Plato

 '[T]here are two things that can ruin and corrupt the rest of our workers.' 

 'What are they?' 

 'Wealth and poverty,' I said.

 'And how do they do it?' 

 'Well, do you think that a potter who has become rich will want to ply his trade any longer?' 

 'No.' 

 'He will become more idle and careless than he was, won't he?' 

 'Much more.' 

 'And so a worse potter.' 

 'Yes, much worse.' 

 'And again, if he is prevented by poverty from providing himself with tools and other necessities of his trade the quality of his work will deteriorate, and his sons and anyone else studying the trade under him will not be taught it so well.' 

 'Inevitably.' 

 'Both poverty and wealth, therefore, have a bad effect on the quality of the work and on the workman himself.'