Czech translation of this post: here 
The following is section no. 43 of “Skirmishes of an Untimely Man” from Friedrich Nietzsche’s The Twilight of the Idols.
43. Whispered to the conservatives. — What was not known formerly, what is known, or might be known, today: a reversion, a return in any sense or degree is simply not possible. We physiologists know that. Yet all priests and moralists have believed the opposite — they wanted to take mankind back, to screw it back, to a former measure of virtue. Morality was always a bed of Procrustes. Even the politicians have aped the preachers of virtue at this point: today too there are still parties whose dream it is that all things might walk backwards like crabs. But no one is free to be a crab. Nothing avails: one must go forward — step by step further into decadence (that is my definition of modern “progress”). One can check this development and thus dam up degeneration, gather it and make it more vehement and sudden: one can do no more.