Arthur Schopenhauer 
The Wisdom of Life [EPUB ebook] 

In these pages I shall speak of The Wisdom of Life in the common meaning of the term, as the art, namely, of ordering our lives so as to obtain the greatest possible amount of pleasure and success; an art the theory of which may be called Eudaemonology, for it teaches us how to lead a happy existence. Such an existence might perhaps be defined as one which, looked at from a purely objective point of view, or, rather, after cool and mature reflection—for the question necessarily involves subjective considerations, —would be decidedly preferable to non-existence; implying that we should cling to it for its own sake, and not merely from the fear of death; and further, that we should never like it to come to an end.