Ask historians doesn't answer homework.

You're question is very broad, how about choosing some specific aspects.

• What major differences were there between Ancient Greek Democracy and modern Democracy? What negative affects would these have?

• How did Spartas citizen training regime affect it's population?

Two ideas, when expanded on can bring up A LOT of negative points regarding the structure of those societies.

Look into it, expand on your knowledge then come back with some specific questions, answers you will receive will generally be very informative and top quality if you ask the right questions!

That seems to me kind of a silly question. Perhaps some refinement is needed. Are you interested in what Greeks thought was negative about their civ? Someone else from the period (perhaps Romans)? Someone from our period? If so, from what civilization? Going back to ancient Greece, are you just looking for elite opinions of Greek civ?

I'm guessing this is a homework assignment. If the question really is to discuss negative aspects of Greek civ, it's a poorly written question because it is so terribly subjective. Given that, a subjective question deserves a subjective answer, so you should probably look into your own opinions on the matter.

Unfortunately I had to remove this thread. As our rules state:

Our users aren't here to do your homework for you, but they might be willing to help. Remember: AskHistorians helps those who help themselves. Don't just give us your essay/assignment topic and ask us for ideas. Do some research of your own, then come to us with questions about what you've learned. This is explained further in this META thread. You can also consider asking the helpful people at /r/HomeworkHelp.