Respectfully Quoted: A Dictionary of Quotations. 1989.
Theodor Reik (18881969)
There are only two roads that lead to something like human happiness. They are marked by the words: love and achievement . In order to be happy oneself it is necessary to make at least one other person happy . The secret of human happiness is not in self-seeking but in self-forgetting.
THEODOR REIK, A Psychologist Looks at Love, chapter 3, final page, in Of Love and Lust, p. 194 (1957).