How we cite our quotes:
My dear dear lord,
The purest treasure mortal times afford
Is spotless reputation; that away,
Men are but gilded loam or painted clay. (1.1.6)
We might think Mowbray is a little passive when he refuses to rat out King Richard for the death of Gloucester, but here we see that he is willing to stick up for himself against Henry Bolingbroke's accusations. In response to the king's demand that Mowbray throw down Henry's gage, Mowbray insists on fighting for his reputation. He's no saint; he seems to have helped to kill Gloucester. But he recognizes how important it is to defend himself against that charge in court. If he refuses to accept Henry's challenge, his reputation will be ruined.
Call it not patience, Gaunt; it is despair.
In suff'ring thus thy brother to be slaughtered,
Thou show'st the naked pathway to thy life,
Teaching stern Murder how to butcher thee.
That which in mean men we entitle patience
Is pale cold cowardice in noble breasts. (1.2.1)
In this play, passivity is destructive, and it almost always ends badly. Here the Duchess of Gloucester tells John of Gaunt that his refusal to avenge his brother's death isn't patience (as he argues), but something worse: it's a decision to condone his brother's murder and accept a pattern of behavior that could very easily lead to his own death. (Gaunt is, after all, Gloucester's brother.) By tolerating this, he's morally guilty of murder, and what he calls patience is simple cowardice.
That England that was wont to conquer others
Hath made a shameful conquest of itself. (2.1.3)
Gaunt bemoans the fact that Richard has "leased" English lands. Richard can be understood to represent England here. By binding the land in this way, the nation doesn't strive or fight for property, bounty, or glory; instead, it (or Richard) signed a piece of paper and "conquered" itself. What's worse, the nobility has let Richard get away with it.