232 PART IV PREPARATORY STAGE. 



the features of one sense are not also features of one or more 

 of the other senses. 



We inquire what features the various classes of sensations 

 possess in common, and what is the degree of the resemblance. 



We strive to discover new classes of sensations. 



We endeavour, following Conclusion 17, to divide each of 

 the classes of sensations into a number of classes of sensations, 

 and we also seek to show that several or all the reputed classes 

 of sensations fall under one head. 



We examine into the elementary facts of any and every class 

 of sensations (ignoring, for the moment, memory, etc.), and deter- 

 mine, following Conclusions 20 and 19, that (a) there is present 

 a stimulus of a particular degree and character persisting for 

 an appreciable period of time ; that (b) the mind is not wholly 

 preoccupied, and is therefore affected and consequently reacts; 

 that (c) the mind must react continuously for a perceptible space 

 of time; that (d) the memory needs to be enlisted for the pur- 

 pose of classing the sensation or experience; and that (e) this 

 implies an attempt at judging and co-ordinating. 



We search for instances where several sensations are sensed 

 simultaneously (as in eating an orange: temperature, touch, 

 smell, taste, sound, effort, and pain), beginning with two sen- 

 sations and gradually increasing their number. 



We endeavour to examine sensations at their minimum inten- 

 sity or clearness (as seeing with eyes approximately or wholly 

 closed) with a view to determining any likeness between sen- 

 sations, and we examine sensations when minimally or margi- 

 nally attended to. 



We examine more or less highly developed and intense sen- 

 sations, and from maximum to minimum, and vice versa. 



We examine whether others' sensations are fundamentally 

 identical with ours, and whether youth, age, etc., or diverse 

 races or periods of history, create any difference, and, if so, 

 the degree of the difference. 



We examine, following Conclusion 20, first the least obscure 

 sensations, such as sight and sound. 



We examine into human activities which are apparently or 

 relatively unaccompanied by sensations, including automatic and 

 reflex actions, and impulses, and minimal sensations when the 

 attention bestowed on them is imperceptible. 



We examine, later, into the nature of pleasure-pain, of the 

 appetites, of internal sensations generally, of the emotions, and 

 whatever other experiences of this character are distinguishable. 



We examine, later still, into the nature of the memory. 



We examine, last, into the processes of systematic feeling, 

 thinking, willing, etc. 



We then complete our enquiry as in illustration I. 1 



1 Mill assumes throughout his Logic that the various senses or classes of 

 sensations are ultimate in character and irreducible. Accordingly, he claims 



