How we cite our quotes: (Line)
Quote #1
They that have pow'r to hurt, and will do none,
That do not do the thing they most do show, (1-2)
The first view we get of the powerful people shows them as isolated in several ways. The first thing that makes them seem isolated is simply the fact that they have power. If you have power to hurt others, this often (but not always) means that you are above them in some way—either because you are more highly placed in the social hierarchy, or because you have some special physical strength. All of these factors separate you from the people you can hurt. The second thing that makes the powerful people isolated is the description of them at the end of line 1 and throughout line 2, where we learn that they keep their true selves hidden inside them. So you could say that these isolated people have their true selves isolated within them.
Quote #2
Who moving others are themselves as stone, (3)
In this line, we get the same sense of isolation that we got from the end of line 1 and line 2: that the powerful people's true selves are hidden within them. It's still anyone's guess whether this is a good thing or a bad thing.
Quote #3
They are the lords and owners of their faces,
Others but stewards of their excellence. (7-8)
Okay, not that we want anyone else to be the lord of our face, but we certainly don't want all our friends and family to be our servants. That's just awkward. And it sounds kind of lonely to boot.
Quote #4
The summer flow'r is to the summer sweet,
Though to itself it only live and die (9-10)
In these lines, we might be seeing the speaker's understanding of isolation shift somewhat. It's hard to get more isolated than that "flow'r" that lives and dies only "to itself." This sense of isolation could be underlined by the fact that Shakespeare has shifted from talking about the plural "They" to this singular flower. But doesn't he seem to be portraying this flower in a pretty positive light? At least, that's what calling it "to the summer sweet" sounds like to us.
Quote #5
But if that flow'r with base infection meet,
The basest weed outbraves his dignity. (11-12)
Here, the speaker seems to go even further in saying that isolation might be good for the flower. If the flower is at risk of infection, isn't that a good reason for it stay secure and protected, far away from whatever might infect it, or what it might infect in turn? Could this be an argument for the powerful people to keep their true natures under wraps as well?