The two foes of human happiness are pain and boredom
Satisfaction consists in freedom from pain, which is the positive element of life.
Nature shows that with the growth of intelligence comes increased capacity for pain, and it is only with the highest degree of intelligence that suffering reaches its supreme point.
It is a clear gain to sacrifice pleasure in order to avoid pain.
The two enemies of human happiness are pain and boredom.
A quick test of the assertion that enjoyment outweighs pain in this world, or that they are at any rate balanced, would be to compare the feelings of an animal engaged in eating another with those of the animal being eaten