MIND-STUFF 279 



and that if the electron is in a human brain, some of the events 

 composing it are likely to be some of the "mental states" of the 

 man to whom the brain belongs. Or, at any rate, they are likely 

 to be parts of such "mental states" — for it must not be assumed 

 that part of a mental state must be a mental state. I do not wish 

 to discuss what is meant by a "mental state"; the main point for 

 us is that the term must include percepts. Thus a percept is an 

 event or a group of events, each of which belongs to one or more 

 of the groups constituting the electrons in the brain. This, 

 I think, is the most concrete statement that can be made about 

 electrons; everything else that can be said is more or less abstract 

 and mathematical. 



I quote this partly for the sake of the remark that it 

 must not be assumed that part of a mental state must 

 necessarily be a mental state. We can no doubt analyse 

 the content of consciousness during a short interval of 

 time into more or less elementary constituent feelings; 

 but it is not suggested that this psychological analysis 

 will reveal the elements out of whose measure-numbers 

 the atoms or electrons are built. The brain-matter is a 

 partial aspect of the whole mental state; but the analysis 

 of the brain-matter by physical investigation does not 

 run at all parallel with the analysis of the mental state 

 by psychological investigation. I assume that Russell 

 meant to warn us that, in speaking of part of a mental 

 state, he was not limiting himself to parts that would 

 be recognised as such psychologically, and he was ad- 

 mitting a more abstract kind of dissection. 



This might give rise to some difficulty if we were 

 postulating complete identity of mind-stuff with con- 

 sciousness. But we know that in the mind there are 

 memories not in consciousness at the moment but 

 capable of being summoned into consciousness. We 

 are vaguely aware that things we cannot recall are lying 

 somewhere about and may come into the mind at any 



