414 Wisconsin Academy of Sciences, Arts, and Letters. 
The missing element. 
The interrogative operation has its analogy with the making 
of a cannon—described, in a. well-worn story, as accomplished 
by taking a hole and putting some iron around it. For the 
moment, I pursue this analogy only so far as to remark that the 
interrogative judgment also 1 starts with, so to speak, a hole. The 
absence of- an element from a previously attempted judgment 
strictly constitutes a mental zero, a vacuum, or say, a void. For 
instance, given the expression “■-killed Lincoln/’ it may be 
assumed that initially no idea whatever is in the mirid, to cor¬ 
respond to what is indicated by the blank.* In using then the 
phrase “the missing element,” or “absent element,” I really wish 
to suggest the void left by the absence of that element. 
The desideratum. 
By this I mean the desired element. Having realized that in 
my attempted judgment there is a void, I next experience, if I 
am to develop an interrogative judgment, a desire for what will 
fill that void. I certainly do not desire the void itself. What 
I do desire is, so to speak, a void-filler. Thus, given “- 
killed Lincoln,” if I base thereon a question, what I shall wish 
to learn and what I shall ask you to tell me, will not be a blank, 
but that which suitably may take the place of the blank. 
That which the blank expresses may be well enough described 
by calling it nothing. That, on the other hand, with which I 
hope in the end to fill the void, is to me quite positively some¬ 
thing. The difference between the two is the difference between 
not being and not being known. The desideratum accordingly 
is to me an indefinite. Expecting to develop this doctrine, I 
note for the moment that, any interrogative word may be ex¬ 
pected to appear as merely a somewhat peculiar modification of 
a corresponding indefinite. 
*Though I be able to say that “Some one killed Lincoln”, or even “An 
actor killed Lincoln”, still, if I ask “Who killed Lincoln?”, it is obvious 
that, so far as compared with any desired judgment—and with this I 
ultimately have to deal—a void exists when I can only say that “Some 
one killed Lincoln”, quite as truly and distinctly as if I were only able 
to say that “-killed Lincoln.” 
