124 STONEY—UNIVERSE OF REAL EXISTENCES. [April 3, 
means existence in a relative sense, namely, what we are to regard 
as existence under the Objective Hypothesis. 
Ordinary language suggests to all who use it a number of mis- 
takes of the kind referred to in the last paragraph. It is, accord- 
ingly, apt to mislead us very much, and we must be constantly 
on our guard against illusions into which we may but too easily be 
led by the usages of common speech, and by associations which 
have grown up around familiar forms of expression. Illusions will 
be found to lurk in what are apparently quite harmless forms of 
expression, such as ‘‘I perceive a cloud moving across the sky’”’ ; 
and to get at what we are really justified in believing, it is well 
diligently to practice ourselves in converting such expressions into 
less misleading forms, wate/ we do so with facility. ‘Thus the fore- 
going statement is equivalent to— 
1. I am a fluctuating group of associated thoughts, and the 
perception of a moving cloud is for a short time one of 
this group. This is an autic group. 
2. The perception of a moving cloud is also a part of another 
group, in which it is joined, not with the other thoughts 
at present in my mind, but with all the other perceptions 
which the antitheton of the cloud could successively pro- 
duce in my mind. 
3. This useful hypothetical group, which may be called the 
objective cloud, is not the cause of my perceptions. Their 
true cause must be sought elsewhere, and, to give it a 
name, it may be called the aitio-cloud, or the onto-cloud. 
It is the antitheton, in the autic universe, of the objective 
cloud. The objective cloud is the protheton of this real 
existence, and is a part of the great hypotheton which we 
call nature. 
Nature is here used to signify the totality of all semszble objecis. 
This definition is in accordance with the usual acceptation of that 
term. 
We have passed successively under review two acts of synthesis 
—the synthesis of the first order, whereby sensations are transformed 
into perceptions ; and the further synthesis, which may be called a- 
synthesis of the second order, whereby perceptions are built together 
into the sensible objects around us, each of which is a kind of 
synopton, or collected view, of materials only a small part of which 
