2 and 4 are both strong. It is clear what is going to be discussed especially on 4. Two is very intreging. It would be nice to see how that will develop. By that it would be interesting to see how those two ideas will be tired together.
One is too vague. It's true, but where are you going with that? Some indication has to be given.
Three has the same problem. Bad? What does bad mean? I may be wrong, but I think a thesis statement, if at all possible, should use concrete nouns. There should be no doubt about where this is going.
This is just an example of what I mean
Throughout history, every time a new technology was developed, it was immediately used in war. I think both 2 and 4 do something like that.
What are the different viewpoints of Frederick Douglass and Captain canot? Fredrick Douglass was a slave that thought that all slaves should be free and Captain Canot was a slave trader that thought that slaves were only good for making money and for manual labor.
