496 PSYCHOLOGY. 



But before considering tlie empirical evidence, let me 

 go on to show tliat there is a certain a priori reason ivhy 

 the kincEsthetic images ought to be the last psychic antecedents of 

 the outgoing currents, and luhy ive should expect these currents 

 to he insentient; ivhy, in short, the soi-disant feelings of inner- 

 vation should NOT exist. 



It is a general principle in Psychology that conscious- 

 ness deserts all processes where it can no longer be of use. 

 The tendency of consciousness to a minimum of complica- 

 tion is in fact a dominating law. The law of parsimony in 

 logic is only its best known case. We grow unconscious 

 of every feeling which is useless as a sign to lead us to our 

 ends, and where one sign will suffice others drop out, and 

 that one remains, to work alone. We observe this in the 

 whole history cf sense-perception, and in the acquisition 

 of every art. We ignore which eye we see with, because a 

 fixed mechanical association has been formed between our 

 motions and each retinal image. Our motions are the 

 ends of our seeing, our retinal images the signals to these 

 ends. If each retinal image, whichever it be, can suggest 

 automatically a motion in the right direction, what need 

 for us to know whether it be in the right eye or the left ? 



read of persons who contract their pupils at will by strongly imagining a 

 brilliant light. A gentleman once informed me (strangely enough I can- 

 not recall who he was, but I have an impression of his being a medical man) 

 that he could sweat at will by imagining himself on the brink of a precipice. 

 The sweating palms of fear are sometimes producible by imagining a ter- 

 rible object (cf. Manouvi-ier in Rev. Phil., xxii. 203). One of my students, 

 whose eyes were made to water by sitting in the dentist's chair before a 

 bright window, can now shed tears by imagining that situation again. 

 One might doubtless collect a large number of idiosyncratic cases of this 

 sort. They teach us how greatly the centres vary in their power to dis- 

 charge through certain channels. All that we need, now, to account for 

 the differences observed between the psychic antecedents of the volun- 

 tary and involuntary movements is that centres producing ideas of the 

 movement's sensible effects should be able to instigate the former, but be 

 out of gear with the latter, unless in exceptional individuals. The famous 

 case of Col. Townsend, who could stop his heart at will, is well known. 

 Sec, on this whole matter, D. H. Tuke: Illustrations of the Influence of 

 the Mind on the Body, chap. xiv. § 3; also J. Braid: Observations on 

 Trance or Human Hybernation (1850). The latest reported case of volun- 

 tary control of the heart i« by Dr. S. A. Pease, in Boston Medical and Sur- 

 gical Journal, May 30, 1889. 



