Happiness does not exclude sadness - if a person responds to life, he's sometimes happy and sometimes sad. What matters is he responds.
Erich FrommReason is man's faculty for grasping the world by thought, in contradiction to intelligence, which is man's ability to manipulate the world with the help of thought. Reason is man's instrument for arriving at the truth, intelligence is man's instrument for manipulating the world more successfully; the former is essentially human, the latter belongs to the animal part of man.
Erich FrommHaving lost religious faith and the humanistic values bound up with it, he [man] concentrated on technical and material values and lost the capacity for deep emotional experiences, for the joy and sadness that accompany them.
Erich Fromm