The Will to Power · Friedrich Wilhelm Nietzsche
966.
In contradistinction to the animal, man has developed such a host of _antagonistic_ instincts and impulses in himself, that he has become master of the earth by means of this synthesis.--Moralities are only the expression of local and limited _orders of rank in_ this multifarious world of instincts which prevent man from perishing through their _antagonism._ Thus a masterful instinct so weakens and subtilises the instinct which opposes it that it becomes an _impulse_ which provides the _stimulus_ for the activity of the principal instinct. The highest man would have the greatest multifariousness in his instincts, and he would _possess_ these in the relatively strongest degree in which he is able to endure them. As a matter of fact, wherever the plant, man, is found strong, mighty instincts are to be found opposing each other (_e.g._ Shakespeare), but they are subdued.
Text from Project Gutenberg, public domain in the United States.