634 THE POPULAR SCIENCE MONTHLY. 



reading, we cast the eye rapidly down the page and, although we 

 do not see one half the words, or a fraction of the letters, yet we 

 catch the sense. If it happens to be a letter from a well-known 

 friend, we read also, as we say, between the lines. Really we read 

 out of our own heads. 



The subjective or a priori factor is simplest, therefore, when, as 

 in the cases given, it is merely the class notion, horse or sugar ; it 

 is most complex when it represents, for instance, a whole system 

 of astronomy, as when, in a falling body, there is apperceived a 

 law of gravitation. But, simple or complex, it follows, first, that 

 unless there be an inner group of ideas to which the object 

 may in some way be referred, knowledge of it is impossible ; and, 

 secondly, that the character of the resulting knowledge depends 

 upon the character of the inner group of ideas. You and 

 I, therefore, see everything to some extent differently. You 

 see things from the standpoint of your previously acquired 

 groups of ideas ; I from mine. Strictly, no two persons can see 

 the same thing in the same way, for it can never happen that 

 two persons have precisely the same groups of ideas relating 

 to any subject. These depend on our past experience, on our 

 education, on the beliefs of our times, on our various sects or 

 parties, on our pet theories, our interests, and our desires. Here 

 is a simple illustration. Suppose an artist and an engineer, stand- 

 ing side by side overlooking a tract of country. What they per- 

 ceive is the same ; what they apperceive is wholly different. To 

 the engineer the country presents itself as a possible line for a 

 railroad, with here advantageous grades and there economic 

 bridges. Before the artist is spread out a landscape, with light 

 and shade and harmony of colors. Suppose, again, a plot of 

 level ground in the suburbs of a city. A college student riding 

 by apperceives it as a possible ball-ground ; a young girl, as a 

 tennis-court ; a speculator, as an addition for town lots ; an under- 

 taker, perhaps, as a possible site for a cemetery. 



In the primary laws of knowing, above stated, we discover 

 the ground principles of the psychology of prejudice. The re- 

 sults may be summed up in the form of two laws : 



1. We see only so much of the world as we have apperceptive 

 organs for seeing. 



2. We see things not as they are but as we are that is, we see 

 the world not as it is, but as molded by the individual peculiari- 

 ties of our minds. 



Applications of the first law I shall state briefly ; of the second, 

 more in detail. The eye is limited by its structure to the recep- 

 tion of ethereal vibrations between the colors red and violet. 

 The ear converts into sound only air-vibrations of a limited 

 rapidity. Just so the mind, in its reception of knowledge, is 



