In which work of Plato, does the character Socrates
 

discuss that the good soldier is a good man even though he is not a philosopher and does not ponder these matters?

I believe this is found in Plato's Republic. In Book II Socrates posits that all men work in that capacity in which they are best suited. There are three classes of people; soldiers, producers and rulers. The role that each class is equally valuable in an ideal city.

It might be or in Phaedrus but I'm having trouble locating the passage I seek.

I also think that's in the Republic.