Question

Why is it important to study both the "good" and "bad" in history?

Answer 1

To learn from it , so that we dont repeat it.

Answer 2

It is important because you can learn from mistakes and change.

Answer 3

In order to know bad from good, one must be familiar with both.

Answer 4

So we know how the world became what it is today.
Not necessarily so we don't repeat it because I'm sure it'll happen again someday in the future. :P