398 Information Storage and Neural Control 



psychons are those of the two-valued logic of propositions. Thus 

 in psychology, introspective, behavioristic or physiological, the 

 fundamental relations are those of two-valued logic. 



Hence arise constructional solutions of holistic problems involving 

 the differentiated continuum of sense awareness and the norma- 

 tive, perfective and resolvent properties of perception and execu- 

 tion. From the irreciprocity of causality it follows that even if the 

 net be known, though we may predict future from present activities, 

 we can deduce neither afferent from central, nor central from 

 efferent, nor past from present activities — conclusions which are 

 reinforced by the contradictory testimony of eye-witnesses, by the 

 difficulty of diagnosing differentially the organically diseased, the 

 hysteric and the malingerer, and by comparing one's own mem- 

 ories or recollections with his contemporaneous records. Moreover, 

 systems which so respond to the difference between afferents to 

 a regenerative net and certain activity within that net, as to 

 reduce the difference, exhibit purposive behavior; and organisms 

 are known to possess many such systems, subserving homeostasis, 

 appetition and attention. Thus both the formal and the final 

 aspects of that activity which we are wont to call mental are 

 rigorously deducible from present neurophysiology. The psychi- 

 atrist may take comfort from the obvious conclusion concerning 

 causality — that, for prognosis, history is never necessary. He can 

 take little from the equally valid conclusion that his observables 

 are explicable only in terms of nervous activities which, until 

 recently, have been beyond his ken. The crux of this ignorance 

 is that inference from any sample of overt behavior to nervous 

 nets is not unique, whereas, of imaginable nets, only one in fact 

 exists, and may, at any moment, exhibit some unpredictable 

 activity. Certainly for the psychiatrist it is more to the point that 

 in such systems "Mind" no longer "goes more ghostly than a 

 ghost." Instead, diseased mentality can be understood without loss 

 of scope or rigor, in the scientific terms of neurophysiology. For 

 neurology, the theory sharpens the distinction between nets neces- 

 sary or merely sufficient for given activities, and so clarifies the 

 relations of disturbed structure to disturbed function. In its own 

 domain the difference between equivalent nets and nets equivalent 

 in the narrow sense indicates the appropriate use and importance 



