Morality

Friedrich Nietzsche identified morality as an error, introduced to human thought through Plato's Forms.  The Platonist view holds that what is 'true', or most real, is something which is other-worldly and can never properly be known, while the (real) world of experience becomes a mere 'shadow' of perfection.  This transcendence also had a parallel growth in Judaism, which prioritized life-denying moral qualities such as humility, obedience, goodness, and maintained through the Christian church.  

Nietzsche saw his life-long task, the revaluing of all values, as rescuing mankind from these errors.  He envisioned a future where individuals acted naturally, using their full natural potential or will to power.  He believed mankind would progress and fulfill this potential only by starting to act naturally and instinctively according to each individual's desires and drives.  Happiness would naturally emerge through this effort.  Nietzsche wanted to prepare the soil for mankind's growth by "re-naturalizing" human drives.  Once we become free of morality (and, by association, of religion) he believed that the coming generations would grow unpolluted, free and strong.

Of course, we saw the fulfillment of this philosophy through the rise of National Socialism in Europe with some 20,000,000 dead a decade later.  Yeah, natural man is nothing to write home about….