I would use some language that helps convey aspects of those themes as well. For example, the use of guilt and manipulation play into those topics as well.

1. Authority figures within Arthur Miller's The Crucible allowed their hopes of maintaining great power interfere with their care for humanity, the purpose of the very offices to which they were appointed.

2. Fear manipulated the town of Salem during Arthur Miller's The Crucible causing a mania that cost people their very lives.

Are you writing a thesis statement in two sentences? What is the purpose of your assignment?

In my opinion, the author of this play is trying to send the message that the authorities in the time of the Salem witch trials were going along with the people's fears just so they (the authorities) could stay in power.  So my sentences would go something like this:

• In this play, Arthur Miller is trying to show that fear makes people believe things that they would not otherwise believe.
• In this play, Arthur Miller is trying to show that authority figures will often care more about keeping their positions of power than they care about doing what is right.