Produced by Barbara Tozier, Bill Tozier, Richard J. Shiffer and the Online Distributed Proofreading Team at http://www.pgdp.net [Transcriber's Note: Every effort has been made to replicate this text as faithfully as possible, including obsolete and variant spellings and other inconsistencies. Text that has been changed to correct an obvious error is noted at the end of this ebook. Also, mismatched single and double quotes remain as they were in the original.] THE ARENA. VOL. XVIII. AUGUST, 1897. NO. 93. [Illustration: David Starr Jordan (with signature)] EVOLUTION: WHAT IT IS AND WHAT IT IS NOT.[1] BY DR. DAVID STARR JORDAN, _President of Leland Stanford Junior University_. [1] Address before the Starr King Fraternity of Oakland, Cal. I. WHAT EVOLUTION IS. This the age of evolution. The word is used by many men in many senses, and still oftener perhaps in no sense at all. By some it is spoken with a haunting dread as though it were another name for the downfall of religion and of social stability. Still others speak it glibly and joyously as though progress and freedom were secured by the mere use of the name. "The word evolution (_Entwickelung_)," says a German writer, "fills the vocal chords more perfectly than any other word." It explains everything, and "puts the key to the universe into one's vest pocket." So various has been the use of the word, so rarely is this use associated with any definite idea, that one hesitates to call himself an evolutionist. "Evolution" and "evolutionist" are almost ready to be cast into that "limbo of spoiled phraseology" which Matthew Arnold has found necessary for so many words in which other generations have delighted, and which they have soiled or spoiled by careless usage. But as the word evolution is not yet put away, as it is the bugbear of many good people, and the "religion" of as many more equally good, it may be worth while to consider what it still means, and what it does not mean. For if we that use the word can agree on a definition, half our quarrel is over. It seems to me that the word evolution is now legitimately used in four different senses. It is the name of a branch of science. It is a theory of organic existence. It is a method of investigation, and it is the basis of a system of philosophy.