Sept. 3, 1874J 



NA TURE 



305 



things lasted, I think, the better part of two years, but sooner or 

 later he recovered from it, and now he is able to walk about with 

 activity, and only by careful measurement can any difference 

 between the two sides and his body be ascertained. The inquiry, 

 the main results of which I shall give you, has been conducted 

 by exceedingly competent persons, and they report that at pre- 

 sent this man lives two lives, a normal life and an abnormal life. 

 In his normal life he is perfectly well, cheerful, does his work as 

 a hospital attendant, and is a respectable, well-conducted man. 

 This normal life lasts for about seven-and-twenty days, or there- 

 abouts, out of every month ; but for a day or two in each month 

 he passes suddenly and without any obvious change into his 

 abnormal condition. In this state ol abnormal life he is still 

 active, gees about as usual, and is to all appearance just the 

 same man as before, goes to bed and undresses himself, gets up, 

 makes his cigarette and smokes it, and eats and drinks. But he 

 neither sees, nor hears, nor tastes, nor smells, nor is he conscious 

 of anything whatever, and he has only one sense organ in a 

 state of activity, namely, that of touch, which is exceedingly 

 delicate. If you put an obstacle in his way, he knocks 

 against it, feels it and goes fo the one side ; if you push him 

 in any direction, he goes straight on until something stops him. 

 I have said that he makes his cigarettes, but you may supply 

 him with shavings or of anything else instead of tobacco, and 

 still he will go on making his cigarettes as usual. His actions 

 are purely mechanical. lie feeds voraciously, but whether you 

 give him aloes or assafoetida, or the nicest thing possible, it is 

 all the same to him. The man is in a condition absolutely 

 parallel to that of the frog I have just described, and no doubt 

 when he is in this condition the functions of his cerebral hemi- 

 spheres are, at any rate, largely annihilated. He is very nearly 

 — I don't say wholly, but very nearly — in the condition of an 

 animal in which the cerebral hemispheres are extirpated. And 

 his state is wonderfully interesting to me, for it bears on the 

 phenomena of mesmerism, of which I saw a good deal when I 

 was a young man. In this state he is capable of performing all 

 sorts of actions on mere suggestion. For example, he dropped 

 his cane, and a person near him putting it into his hand, the feel- 

 ing of the end of the cane evidently produced in him those 

 molecular changes of the brain which, had he possessed con- 

 sciousness, would have given rise to the idea of his rifle ; for he 

 threw himself on his face, began feeling for his cartridges, went 

 through the motions of touching his gun, and shouted out to an 

 imaginary comrade, " Here they are, a score of them ; but we 

 will give a good account of them." But the most remarkable 

 fact of all is the modification which this injury has made in the 

 man's mor.al nature. In his normal life he is an upright and 

 honest man. In his abnormal state he is an inveterate thief He 

 will steal everything he can lay his hands upon, and if he cannot 

 steal anything else, he will steal his own things and hide them 

 Qway. 



Now, if Descartes had had this fact before him, need I 

 tell you that his theory of animal automatism would have been 

 enormously strengthened ? lie would have said: "Here is a 

 case of a man performing actions more complicated, and to all 

 . appearance more dependent on reason, than any of the ordinary 

 operations of animals, and yet you have positive proof that these 

 actions are purely mechanical. What, then, have you to urge 

 against my doctrine that all animals are m.ere machines ? " In 

 the words of Malebranche, who adopted Descartes' view, " In 

 dogs, cats, and other animals, there is neither intelligence nor 

 piritual soul as we understand the matter commonly ; they eat 

 without pleasure, they cry out without pain, they grow without 

 knowing it, they desire nothing, they know nothing, and .f they 

 act with dexterity and in a manner which indicates intelligence, 

 it is because God having made them with the intention of pro- 

 serving them. He has constructed their bodies in such a manner 

 that they escape organically, without knowing it, everything 

 which could injure them and which they seem to iear." 

 Descartes put forward this hypothesis, and I do not know that 

 it can be positively refuted. We can have no direct observation 

 of consciousness in any creature but ourselves. Cut I must say 

 for myself— looking at the matter on the ground of analogy- 

 taking into account that great doctrine of continuity which for- 

 bids one to suppose that any natural phenomena can come into 

 existence suddenly and without some precedent, gradual modifi- 

 cation tending towards it, and taking into account the incontro- 

 vertible fact that the lower vertebrated animals possess, in a less 

 developed condition, that part of the brain which we have every 

 reason to believe is the organ of consciousness in ourselves, it 

 seems vastly more probable that the lower animals, although 



they may not possess that sort of consciousness which we have 

 ourselves, yet have it in a form proportional to the comparative de- 

 velopment of the organ of that consciousness, and foreshadow more 

 or less dimly those feelings which we ]50ssess ourselves. I think 

 tliat is the most rational conclusion that can be come to. It has 

 this advantage, though this is a consideration which could not 

 be urged in dealing with questions that are susceptible of demon- 

 stration, but which is well worthy of consideration in a case like 

 the present, that it relieves us of the very terrible consequences 

 of making any mistake on this subject. I must confess that, 

 looking at the terrible struggle for existence which is everywhere 

 going on in the animal world, and considering the frightful 

 quantity of pain with which that process must be accompanied, 

 if animals are sensitive, I should be glad if the prol^abilitias were 

 in favour of the view of Descartes. But, on the other hand, 

 considering that if we were to regard animals as mere machines, 

 we might indulge in unnecessary cruelties and in careless treatment 

 of them, I must confess I think it much better to err on the right 

 side, and not to concur with Descartes on this point. 



But let me point out to you that although wc may come to the 

 conclusion that Descartes was wrong in supposing that animals 

 are insensible machines, it does not in the slighest degree follow 

 that they are not sensitive and conscious automata ; in fact, that 

 is the view which is more or less clearly in the minds of every 

 one of us. When we talk of the lower animals being provided 

 with instinct, and not with reason, what we really mean is, tha 

 although they are sensitive and although they are conscious, yet 

 they act mechanically, and that their different states of con- 

 sciousness, their sensations, their thoughts (if they have any), 

 their volitions (if they have any), are the products and conse- 

 quences of their mechanical arrangements. I must confess that 

 this popular view is to my mind the only one which can be scientifi- 

 cally adopted. We are bound byeverything we know of the opera- 

 tions of the nervous system to believe that when a certain molecular 

 change is brought about in the central part of the nervous system, 

 that change, in some way utterly unknown to us, causes that state 

 of consciousness that we term a sensation. It is not to be doubted 

 that those motions which give rise to sensation leave in the brain 

 changes of its substance which answer to what Haller called 

 " '<\-s/ix'ia rcntm" and to what that great thinker, David ITarlley, 

 termed ' ' Vibratiuncules. " The sensation which has passed away 

 leaves behind molecules of the brain competent to its reproduc- 

 tion — "sensigenous molecules," so to speak — which constitute 

 the physical foundation of memory. Other molecular changes 

 give rise to conditions of pleasure and pain, and to the emotion 

 which in ourselves we call volition. I have no doubt that is the 

 relation between the physical processes of the animal and his 

 mental processes. In this case it follows inevitably that these states 

 of consciousness can have no sort of relation of causation to the 

 motions of the muscles of the body. The volitions of animals 

 will be simply states of emotion which precede their actions. To 

 make clear what I mean, suppose I had a frog placed in my 

 hand, and that I could make it, by turning my hand, perform 

 this balancing movement. If the frog were a philosopher, he 

 might reason thus : — " I feel myself uncomfortable and slipping, 

 and, feeling myself uncomfortable, I put my legs out to save 

 myself Knowing that I shall tumble if I do not put them 

 further, I put them further still, .and my volition brings about all 

 these lieautiful adjustments which result in my sitting safely." 

 But if the frog so reasoned, he would be entirely mistaken ; for 

 the frog does the thing just as well when he has no reason, no 

 sensation, no possibility of thought of any kind. The only con- 

 clusion, then, at which there seems any good ground for arriving 

 is that animals are machines, but that they are conscious 

 machines. 



I might with propriety consider what I have now said as the 

 conclusion of the observations which I have to offer concerning 

 animal automatism. So far as I know, the problem which we 

 have hitherto been discussing is .an entirely open one. I do not 

 know that there is any reason why any person, whatever his 

 opinions may be, should be prevented, if he be so inclined, 

 from accepting the doctrine which I have just now put before you. 

 So far as we know, animals are conscious automata. That doc- 

 trine is perfectly consistent with any view that we may choose to 

 take on the very curious speculation — Whetlier animals possess 

 souls or not, and if they possess souls, whether those souls are im- 

 mortal or not. The doctrine to which I have referred is not incon- 

 sistent with the perfectly strict and literal adherence to the Scripture 

 text concerning "the beast that perisheth," nor, on the other 

 hand, does it prevent anyone from entertaining the amiable con- 



