Both Tang. Parts of (our) history should be glorified, and ALL of our history should be remembered, even studied, because PARTS of our history SHOULD be remembered for its shame, in the hope that we, as a people, learn from it and don't commit such shameful acts again. It's supposedly the only thing that separates us from the rest of the animals (the so-called ability to reason) though I, personally, don't see much evidence of much learning by most folks!
Making the same mistakes over and over is way dumber than ANY dog I ever had.