82 PSYCHOLOGY. 



still exist inside of the perception and form a constituent 

 thereof. The sensation is one thing and tlie perception 

 another, and neither can take place at the same time with 

 the other, because their cerebral conditions are not the 

 same. They may resemble each other, but in no respect are 

 they identical states of mind. 



PERCEPTION IS OF DEFINITE AND PROBABLE THINGS. 



The chief cerebral conditions of perception are the ]3aths 

 of association irradiating from the sense-impression, which 

 may have been already formed. If a certain sensation be 

 strongly associated with the attributes of a certain thing, 

 that thing is almost sure to be perceived when we get the 

 sensation. Examples of such things would be familiar 

 people, places, etc., which we recognize and name at a 

 glance. But where the sensation is associated with more than 

 one reality, so that either of two discrepant sets of resid- 

 ual properties may arise, the perception is doubtful and 

 vacillating, and the most that can then he said of it is that it 

 iC'ill he of a peobable thing, of the thing which would most 

 usually have given us that sensation. 



In these ambiguous cases it is interesting to note that 

 perception is rarely abortive ; some perception takes place. 

 The two discrepant sets of associates do not neutralize each 

 other or mix and make a blur. What we more commonly 

 get is first one object in its completeness, and then the other 

 in its completeness. In other words, all hrain-processes are 

 sitch as give rise to what we may call figuked consciousness. If 

 paths are irradiated at all, they are irradiated in consistent 

 systems, and occasion thoughts of definite objects, not mere 

 hodge-podges of elements. Even where the brain's func- 

 tions are half thrown out of gear, as in aphasia or dropping 

 asleep, this law of figured consciousness holds good. A 

 person who suddenly gets sleepy whilst reading aloud will 

 read wrong ; but instead of emitting a mere broth of sylla- 

 bles, he will make such mistakes as to read ' supper-time ' 

 instead of ' sovereign,' ' overthrow ' instead of ' opposite,' 

 or indeed utter entirely imaginary phrases, composed of 

 several definite words, instead of phrases of the book. So 

 in aphasia : where the disease is mild the patient's mis- 



