Do not smile at my advice -- the advice of a dreamer who warns you against Kantians, Fichteans, and philosophers of nature. Do not smile at the visionary who anticipates the same revolution in the realm of the visible as has taken place in the spiritual. Thought precedes action as lightning precedes thunder.German thunder is of true Germanic character; it is not very nimble, but rumbles along ponderously. Yet, it will come and when you hear a crashing such as never before has been heard in the world's history, then you know that the German thunderbolt has fallen at last. At that uproar the eagles of the air will drop dead, and lions in the remotest deserts of Africa will hide in their royal dens. A play will be performed in Germany which will make the French Revolution look like an innocent idyll."
The History of Religion and Philosophy in Germany, Heinreich Heine, 1834