X PREFACE 
possession of the human race, and to know how we came 
to acquire it, as to possess the information which is our 
rich heritage. 
5. Impress upon him the present limitations of our 
knowledge, and acquaint him with some of the more 
important problems awaiting solution. 
6. Enlist his interest in the science by so presenting 
it as to make him sense its importance and value to human 
life in general, and to his own life in particular, and thereby 
stimulate him to pursue the study further, and, may be, 
to the point of making his own original contributions. A 
class that is properly taught can never inquire, at the end 
of the course, "What is the use of knowing all that?" 
Outside of technical and professional schools, no intro- 
ductory course in any subject should ever be planned or 
presented on the supposition that its main purpose is to 
pave the way for more advanced courses. The main func- 
tion of all introductory courses is, as the name implies, to 
introduce the pupil to a new realm of thought, to acquaint 
him with a possible new interest in life. If he be led to 
discover himself in this new realm well and good; if not 
well and good also; he will find himself elsewhere, but 
will always be enriched and liberalized from the widening 
of his mental horizon by contact with another discipline 
than his major interest in life. 
In presenting an elementary course, the aim should not 
be to make the subject simple to remove all difficulties 
but to make it really interesting, that is, significant to the 
pupil in his own life, and to make it as rich as possible as 
a revelation of those broad basic principles which are fun- 
damental to all true culture, but which are to be amplified 
and more deeply investigated only in more advanced 
