"The Data of Ethics" is a book written by Herbert Spencer who was an English sociologist,
philosopher, anthropologist, and biologist. The book was published in 1879 and "Spencer
continues his exploration of individualist moral philosophy in this book. He examines the
nature of human conduct, different ways in which conduct might be judged, the conflict
between egoism and altruism, and what he calls absolute ethics."
If you follow the link you will be lead to the source of the quotation and if you are interested
into Spencer's work you can read the complete book.
Bibliography:
Spencer, Herbert. The Data of Ethics. London: Williams and Norgate, 1879. The Online Library of Liberty. Web. 06 Oct. 2013 <http://oll.libertyfund.org/?option=com_staticxt&staticfile=show.php%3Ftitle=3 31&Itemid=27>.