History is one long chain of reflections. Hegel also indicated certain rules that apply for this chain of reflections. Anyone studying history in depth will observe that a thought is usually proposed on the basis of other, previously proposed thoughts. But as soon as one thought is proposed, it will be contradicted by another. A tension arises between these two opposite ways of thinking. But the tension is resolved by the proposal of a third thought which accommodates the best of both points of view. Hegel calls this a dialectic process
Jostein Gaarder