106 KANSAS CITY REVIEW OF SCIENCE. 
contact with other objects is clearly implied in Dr. Porter’s analysis of the know- 
ing process: ‘‘To know always involves two comprehensive acts, each of which 
corresponds to the other—the act of separating or revolving objects as wholes 
into their parts, and the act of uniting or combining these parts into their 
wholes.” 
Concepts are founded upon percepts, but the former are rarely permanent, 
complete and triumphant. Perfect conceptions require experiences rendered per- 
fect by varied, like and similar conditions. Such symbolic knowledge, saving us 
the necessity of returning to sensual experiences, supplies every want and answers 
every purpose which symbols can provide, and with these the future progress of 
the pupil is mainly concerned. ‘These truths must be granted; then, have we 
not a clear necessity for emphasizing the duty of making the child’s perceptions 
not only complete but systematic? Every primary school should be provided 
with abundant apparatus, for instance, the units of length, weight and capacity. 
With these the pupil should be allowed to make the measurements for himself, 
whereby he practically determines the gills and gallons, the inches and yards, the 
ounces and tons. Thus do the gills, inches and ounces, as perceived facts, 
become the gills, inches and ounces of truly conceived facts. ‘‘ True perceptions 
form the basis of intellect.”{ It can not be too strongly insisted that personal 
experience is the sole requirement for personal acquisition, and this knowledge, at 
first intuitively gained, becomes knowledge symbolically known. Knowing the 
full force of these psychological truths, an eminent educator* has well said that 
‘¢in regard to science, our schools are not above those of the Middle Ages—then, 
the students repeated the obscure statements of Aristotle, while now students 
repeat the statements of their text-books, without obtaining any valid ground for 
the conviction they are required to express.” It is not difficult to compare some 
traits in the character of two individuals, one of whom has made science the 
usual literary study, as witnessed in most of the schools throughout the country, 
the other of whom has been drilled in the practical methods which a correct study 
of natural phenomena demands. ‘The first 
Has learned how useful are devices, , 
And gives all honor to inventors ; 
‘‘Promptness,” he terms a business virtue, 
Historic, importance, he says, it hath not, 
Ampére, he calls the mightiest intellect, 
Familiarly quotes from works of Bacon. 
Adroitly speaks of heed and caution, 
Cites stunning things that have existed— 
Whose nebulous causes are historic, 
(Is sure he read it in the text-book). 
Dilates upon the accidental, 
Declares the causes supernatural. 
The second 
5 Clears the way with new devices; 
Execution nerves his sinews, 
Judgment, prompt and vigorous action 
Make many blessings fly about him, 
t The Art of Scientific Discovery. —GorE. 
* Prof. Hinrichs, University of Iowa. 
