Philosophy of history was one of the most popular branches of philosophy in the 19th. Century. During this century, a great number of philosophers in
Hegel also believed that there is a real progress of human history. He said, history is a process through which reason (the absolute reason or spirit) reveals itself. His reason is not just a human faculty. It is the total reality itself. He insisted that every historical event follows the law of reason and so should be regarded as a realization of the intention of that reason. In each step of the historical development, reason manifests itself, and every event takes place exactly according to the level of the spirit of that age. As a result, Hegel says, “what is rational is that which is real, and what is real is that which is rational.” Since a historical event is nothing but a momentum of the reason, nothing can happen which is not to be happened. In this sense, it is not possible to think out any historical event which does not correspond to the level of self-developing reason and is so deviated from the line of progression.
Like Hegel, Kant believed also that the human history makes progress. But in contrast to Hegel, his idea of historical progress is a kind of postulate. A postulate is an assumption which is self-evident or generally accepted without proof, especially when used as a basis for an argument. Only when we accept the idea of a historical progress, Kant believed, we can regard the human history as something that has meaning. Without such an idea one would loose oneself in a hotchpotch of contingent historical facts. We cannot understand or even identify the historical facts until we think that they should show progress indeed. Reversely, the possibility of an actual progress in history depends on the attitude of humankind itself. It means, only if we are ready to accept the idea of history and try to make historical events which accord with that idea, the historical progress will be realized. Historians as empirical scientists start from the historical facts while philosophers interested in history start from the idea and then go to the facts. Kant proposed also with respect to history, we can say, a Copernican Revolution.