Complete this sentence: I want happiness because …
It is impossible to complete the sentence!
The word happiness is used to name that which is desirable solely for itself and not as a means to anything else.
Of anything else that one wants, it is always possible to say, “I want it because it will contribute to my happiness”. That is, the thing he wants is not the end of his striving, he has not arrived at his ultimate good — his happiness.
Definition of “Ultimate”: for something to be ultimate in any dimension or direction, it must be that beyond which one cannot go.
Happiness is an ultimate.
— From Six Great Ideas, by Mortimer Adler