Page:Mind (New Series) Volume 9.djvu/399

 PERCEPTION OF ORANGE AND DURATION. SK.'i Such simple change-consciousnesses in all their primitive simpli- city are not uncommon, but they are apt to be overlooked because their vagueness renders them useless for the purposes of accurate thinking or practical doing. They are characteristic of our lazy times ; but in our times of purpose and pursuit they are not the direct objects of our attention. Either they have acquired a de- finite meaning in the usual way of acquirement of meaning, so that this change-experience means the change from A to B and that the change from C to D, this the succession of two raps and that the succession of three, and then it is the meaning which has interest for us ; or, where the meaning is not clear, we make use of reflective comparison, of which more must be said presently. Here a word must be added as to the case when B follows A with great rapidity. Mr. Shadworth Hodgson asks in the last number of MIND (p. 242) whether " Dr. Stout's two eminent German authorities have made it impossible to suppose that we can ever in immediate perception hear, say, a postman's double rap, or distinguish it in immediate perception from a single rap ". The answer is that, if the postman raps quickly enough, the two knocks would fall within the same psychical moment or present, that is, within one apprehension ; and they would be distinguishable from a single knock, not because the first rap is present as a memory when the second is apprehended, but because the total impression differs. 2. Relations of Intensity or Quality. The difficulty of com- paring successive presentations A and B seems to depend upon three factors, the actual amount of difference between A and B, our purpose in comparing them, and the time-interval between them. The difference between A and B varies from 'nil' through the just-noticeable upwards ; our task may vary from simply judg- ing ' equal ' and ' different ' to assigning a position to the different, such as 'stronger' or 'weaker,' 'higher' or 'lower,' etc. ; and with regard to the time-interval, too rapid a succession flurries us, whilst too slow a succession may make comparison altogether impossible. Granted a suitable rate of succession, the easiest task is, of course, to judge as merely ' different ' a more than noticeable difference, the hardest to assign a position to one that is only just noticeable ; and between these limits are many grades of ease and difficulty. Now if we leave aside the case where A and B are judged equal or the same, it seems a priori probable that the mental processes involved in judging difference will vary with the difficulty of drawing the comparison. Whether this is so only those can finally decide who have subjected themselves to a long course of self-observation under conditions of experiment, and in saying that it does seem to me to be true, I speak with a full knowledge of the weakness of every-day observation in regard to these fine points. However, from such rough tests as I have been able to apply to myself, I incline to think that at any rate in my own case the facts are somewhat as follows : (1) When the task 25