If humans differ from other animals, it is partly in the conflicts of their instincts. They crave security, but they are easily bored; they are peace-loving animals, but they have an itch for violence; they are drawn to thinking, but at the same time they hate and fear the unsettlement thinking brings.
There is no way of life in which all these needs can be satisfied. Luckily, as the history of philosophy testifies, humans have a gift for selfdeception, and thrive in ignorance of their natures.
Morality is a sickness peculiar to humans, the good life is a refinement of the virtues of animals. Arising from our animal natures, ethics needs no ground; but it runs aground in the conflicts of our needs.
Straw Dogs, John Grey, 2004.