^UNE 18, 1903] 



NATURE 



SI 



lits respectively, and without mutual action. The total 

 lergy is ni(9*+i-) = 82m, the total momentum due north 

 2wi(9+i), that due east is zero. At 12 o'clock the sprite 

 nils that the first body should diminish its velocity due 

 )rth to 5 and get one of 4 due east, while at the same 

 yme the second shall increase its velocity to 5 due north 

 id get one of 4 due west. The bodies obey the sprite, of 

 )urse, and even though he has by no means confined him- 

 •If to " guiding or controlling forces," the energy re- 

 gains the same, for ni(5^-f-4- + 5- + 4^)— 82m, and the total 

 momentum north is 2m(5 + 5), and that east is 2^1(4-4), 

 i.e. 20m and o, the same as before. 



Now suppose a materialistic philosopher had been observ- 

 \g all this. Before 12 o'clock his observations of the 

 >ntinued uniform motion of the bodies would have led 

 im to conclude that there was no mutual action between 

 them, i.e. the law of the force was that it was zero. At 

 12 o'clock he would observe a change, and if ignorant that 

 there was a sprite, would conclude that some other system, 

 unseen by him, had come into collision with his system. 

 If he is assured this is not the case, he will be driven 

 to the only alternative, viz. that at 12 o'clock the law 

 of the action between them had suddenly changed. (For 

 the philosopher to say that a force had acted on the balls 

 at 12 o'clock would be merely another way of saying that 

 their motion had changed, because the definition of 

 force, derived from Newton's laws, is " that which changes 

 the state of motion of a body." Hence, whether he thought 

 the action was due to a sprite, to an external material 

 system, or to a change in the law of action between the 

 bodies, the statement that at 12 o'clock a force had acted 

 on each would be equally appropriate, and whatever sup- 

 position be adopted, the force would have the direction and 

 magnitude, viz. that deduced by Newton's laws from the 

 observed changes in the motion.) 



Replace the two particles by the entire universe, and the 

 point in dispute is really this. The physicist says, the 

 rhanees in the motion of each particle at any instant 

 depend solely on the positions of it and all the other 

 jiarticles, according to laws which do not change with the 

 lime. The form of the dependence, too, shows that there 

 is but one future course of the motion — k.K-it.v.'s singular 

 solutions do not come in — and that it only needs infinite 

 mathematical knowledge to calculate, from the positions 

 and velocities at 12 o'clock to-day, and the unalterable 

 laws of mutual action, what every particle of the system 

 will be doing at, say, 3 o'clock three hundred years hence. 



It is open to anyone to deny this position, but he ought, 

 I think, to state exactly how far he does deny it, even 

 though he may not be able to state exactly what he wishes 

 to substitute for it. What it seems to me necessary for 

 Sir Oliver Lodge to deny is that these laws apply to living 

 matter. He must say that if the motions of the 

 material particles of which protoplasm is composed be ex- 

 amined (in conjunction, of course, with those of 

 the rest of the universe), our materialistic philosopher 

 would be compelled to conclude that a change in the law 

 of action had taken place — just as he would in the case of 

 the two particles, if he were certified that they composed 

 the whole universe. The materialist philosopher would 

 then, I imagine, be prepared to receive with attention, at all 

 • vents. Sir Oliver's assurance that these extraordinary 

 changes were due to an exertion of will- or psychic-power 

 on the part of the protoplasm, and that the law of mutual 

 action between the material particles was not changed at 

 all — it was only " supplemented," I suppose he would say, 

 by the action of mind on matter. 



Whether this is really so or not is perhaps open to that 

 reasonable doubt which may exist on any matter which has 

 not been made the subject of conclusive experiment, and 

 any man is entitled to say that he doubts whether an observ- 

 ation of the motions of live matter would not reveal some- 

 thing incompatible with the supposition that the " forces " 

 acting on the particles of the universe are determined 

 according to any fixed law, i.e. a law independent of the 

 time. 



It would be interesting, but inappropniate, to discuss how 

 far such a supposition will help people in regard to " the 

 elTicacy of prayer and many another practical outcome of 

 religious belief," the reality of which Sir Oliver and many 

 ethers consider to depend on the attitude taken in regard 



NO. 1755, VOL. 68] 



to it. Practically the effect of a general adoption of the 

 supposition would be that for many years to come it would 

 be thought to have removed the difficulties, but after a 

 time these would crop up exactly as before. When men 

 became more familiar with the conception of spirit, they 

 would ask of it also, what laws it followed, and in the 

 mental, as in the physical world, the conception of a neces- 

 sary law of operation would assert its absolute sway among 

 the higher minds who make knowledge their object. For 

 it is only that which is subject to law which can be the 

 object of knowledge. That which is capricious can only 

 be the subject of memory and conjecture. It is not in this 

 direction that any permanent solution of difficulties is to be 

 sought. Edward P. Culverwfxl. 



Trinity College, Dublin, May 28. 



In relation to the letters on " Psychophysical Inter- 

 action " appearing in Nature, the initial questioning the 

 discussion works back to is whether we are to recognise 

 in mind the mere knower, or manipulator, as well, of 

 animal action. In relation to such a questioning it may 

 be of use to consider that what is inferred concerning mind 

 as existing anywhere outside oneself is inferred by study 

 of action displays. We possess no faculty which can 

 directly become aware of the psychical outside' oneself. It 

 is in action we see it, if at all. The study of animal in- 

 telligence infers as to animal intelligence by seeing it in 

 animal action. We meet with peculiar kinds of actions 

 which seem to require intelligence for their origin ; and 

 therefore surmise as to animal intelligence. The observ- 

 ation holds of the human intelligences with which we come 

 in contact. We can only get to know the mind of a man 

 through his action that he acts intelligently ; therefore he 

 must be intelligent. A man may speak his ideas to us, and 

 by his speaking convince us of his inlying intelligence ; but 

 in ultimate analysis talking is as much a muscular per- 

 formance as walking. Or he may write his thoughts, and 

 we by reading may see in what he has written that he has 

 ideas'; but if the mind is mere knower it cannot manipu- 

 late action to the writing down of ideas, and therefore this 

 is effected in some other way. For all we may know to the 

 contrary, the man vacant of mind may be more at large 

 than we are apt to suspect, for by the mechanical hypothesis 

 a man mav talk rationally and yet not have ideas. 



The mechanical hypothesis disposes of the actions of 

 animals by the theory of their being fitted and adapted in 

 reciprocal relation to environment by process of natural 

 selection. Variations in action take place in species, and 

 the species which are favoured with favourable variations 

 in action in the long run survive. The theory explains 

 manv of the adjustments of animal action, but not all. 

 There are instances to which the hypothesis can never ex- 

 tend, and they are the instances of action which are put 

 in in circumstances where there is no scope for natural 

 selection to work. Take, for instance, a man learning to- 

 play a cornet. The learning to play a cornet is the putting 

 in of an action process, and as such is worthy of biologic 

 consideration. The man learns to play the instrument by 

 manipulating his breathing and fingering the keys. He 

 studies the music before him, and internally, and mentally, 

 decides upon the fingering which is appropriate. His 

 breathing into the instrument is timed by his mental trans- 

 lation of signs given by the printed page. Each stage 

 of his practising is revised by hearing. Where he plays a 

 false note he goes back, and exercises e.xtra attention to 

 do better. 



The entire action of players in a cricket field is action 

 adjusted in relation to the motion of the ball. It is actiori 

 determined by seeing. Deduct the seeing and it cannot be 

 done. And cricket has not been long enough in existence 

 for natural selection to have anything to do with it. Sa 

 the editing of Nature is an intelligent-mechanical process. 

 Deduct the intelligence in that process, and it cannot be 

 done. The expert conjurer, equilibrist, or trick cyclist 

 depends upon the alertness of his sensations for the correct- 

 ness of his performance. 



.\pparently in the whole proceeding of animal action^ 

 excepting the old established automatic, knowing, seeing, 

 hearing, feeling, plays its part. Ants will eat sugar but 

 not saccharin. The taste to them is not as sugar. So 



