CLASSES OF LIFE
THE problems to be dealt with in this chapter are not easy, but they are exceedingly important. To classify phenomena correctly, they must be correctly analysed and clearly defined. For the sake of clearness I will use the simplest illustrations and, avoiding as much as possible the difficulties of technical terms, will use language easily to be understood by every one. In some cases the words will indeed have a technical meaning and it will be necessary to exercise great care against the danger of giving false impressions; for clear ideas are essential to sound thinking. As a matter of fact our common daily speech is ill adapted for the precise expression of thought; even so-called "scientific" language is often too vague for the purpose and requires further refining. Some may say that it is useless and unnecessary to lay so much stress on correct thinking and precise expression; that it has no practical value; for they say that "business" language is good enough to "talk business," or to put "something over"--the other fellow. But a little explanation will show that precision is often of the greatest importance.