November 26, 1891] 



NATURE 



83 



seen to be true. Any man who really doubted whether, if 

 his legs were cut off, they might not at the same time 

 remain on, would have a mind in a diseased condition. 



There is, however, another reason which indisposes 

 some persons to see the necessary force of this law. It 

 is due, I think, to a second fact of mental association. 



Things which are very distant, or which happened a 

 long time ago, are known to us only in roundabout 

 ways, and we often feel more or less want of certainty 

 about them. On the other hand, we have a practical 

 certainty concerning the things which are about us at any 

 given moment. Thus we have come to associate a feeling 

 of uncertainty with statements about things very remote. 

 But nothing can well be more remote from us than " the 

 most distant regions of space " or " before the origin of the 

 solar system." It is not surprising, then, that this mental 

 association should call forth a feeling of uncertainty with 

 respect to any statement about universal truth. 



It is, no doubt, wonderful that we should be able to 

 know any necessary and universal truths ; but it is less 

 exceptionally wonderful, when we come to think the matter 

 all round, than it may at first sight appear to be. It is 

 wonderful ; but so, deeply considered, is all our know- 

 ledge. It is wonderful that through molecular vibrations, 

 or other occult powers of bodies, we have sensations- 

 such as of musical tones, sweetness, blueness, or what 

 not. It is wonderful that through sensations, actual and 

 remembered, we have perceptions. It is wonderful that 

 on the occurrence of certain perceptions we recognize our 

 own existence past and present. So, also, it is wonderful 

 that we recognize that what we know '■'■is" cannot at the 

 same time " not be." The fact is so, and we perceive it 

 to be so ; we know things, and we know that we know 

 them. How we know them is a mystery, indeed, 

 but one about which it is, I think, perfectly idle to 

 speculate. It is precisely parallel to the mystery of 

 sensation. We feel things savoury, or odorous, or brilliant, 

 or melodious, as the case may be, and with the aid of the 

 scalpel and the microscope we may investigate the material 

 conditions of such sensations. But how such conditions 

 can give rise to the feelings themselves is a mystery 

 which defies our utmost efforts to penetrate. I make no 

 pretension to be able to throw any light upon the problem 

 " How is knowledge possible .' " any more than on the 

 problem " How is sensation possible.'" or on the ques 



tions "How is life possible i 



How is extension 



possible." But " Ignorantia modi non tollit certitudijicm 

 factij" And we know that we are living, that we feel, 

 and that we do know something— if only that we know 

 we doubt about the certainty of our knowledge. 



And dpropos of such doubt, let me here put before you 

 the intellectual penalties which have to be paid for any 

 r^rt/and serious doubt with respect to the implications of 

 science. I think we shall see that nothing less than in- 

 tellectual suicide or mental paralysis must be the result. 

 And such a result must also be logically fatal to every 

 branch of science. The first implication I put before you 

 was the validity of inference. 



Now, no one who argues, or who listens to or reads — 

 with any serious intention — the arguments of others, can, 

 without stultifying himself, profess to think that no pro- 

 cess of reasoning is valid. If the truth of no mode of 

 reasoning is certain, if we can make no certain inferences 

 at all, then all arguments must be useless, and to proffer, 

 or to consider, them must be alike vain. But not only 

 must all reasoning addressed to others be thus vain, the 

 silent reasoning of solitary discursive thought must be 

 vain also. Yet what does this amount to save an utter 

 paralysis of the intellect ? It is scepticism run mad. 



But the implication I regard as one of the most im- 

 portant of all is the implication of otir knowledge of our 

 own continuous existence, concerning which I said I 

 must crave your permission to speak at some length. It 

 was the mention of this implication which led me to 



NO. I 152, VOL. 45] 



refer to that system of thought it is my object here to 

 controvert. 



I have heard it proclaimed in this theatre by Prof. 

 Huxley that we cannot have supreme certainty as to our 

 own continuous existence, and that such knowledge is 

 but secondary and subordinate to our knowledge of our 

 present feelings or " states of consciousness." 



Of course I am not thus accusing him of originating 

 any such erroneous view. In that matter he is but a 

 follower of that daring and playful philosopher Hume. I 

 say "playful," because I cannot myself think that he 

 really believed his own negations. He seems to me too 

 acute a man to have been himself their dupe. But how- 

 ever this may be, I here venture directly to contradict 

 Hume's and Prof. Huxley's affirmation, which is also 

 adopted by Mr. Herbert Spencer, and to afifirm that we 

 have the highest certainty as to our own continuous 

 existence. 



It is, of course, quite true that we have complete 

 certainty about our present feelings, as also that we can- 

 not know ourselves apart from our feelings. But it is no 

 less true that we cannot be conscious of feelings apart 

 from the "self" which his those feelings. Now, it is 

 assumed by those I oppose that we can know nothing 

 with absolute certainty unless we know it by itself or 

 " unmodified," or as existing "absolutely" But in fact 

 nothing, so far as we know, exists apart from every other 

 entity and unmodified — or " absolutely" as it is, in my 

 opinion, absurdly called. No wonder, then, if we do not 

 know things in a way in which they never do, and 

 probably never can, exist. We can really know nothing 

 by itself because nothing exists by itself. It is not 

 wonderful, then, if we only know ourselves as related to 

 our simultaneously known feelings, or vice versd. 



It is quite true that we never know our own substantial 

 essential being alone and unmodified, but then we have 

 never for an instant so existed. Our knowledge of ourselves 

 in this respect is like our knowledge of anybody and 

 everybody else. Most persons here present doubtless 

 know Prof. Tyndall, yet they never knew him, no 

 one ever knew him, except in some " state"— either 

 at home or away from home, either sitting or not 

 sitting, either in motion or at rest, either with his 

 head covered or uncovered — and this for the very 

 good and obvious reason that he never did or could 

 exist for a moment save in some " state." But this 

 does not prevent your knowing him very well, and the 

 same consideration applies to our knowledge of ourselves. 

 When I consider what is my primary, direct conscious- 

 ness at any moment, I find it to be neither a conscious- 

 ness of a " state of feeling '' nor of my " continuous exist- 

 ence," but a consciousness of doing something or having 

 something done to me — action or reaction. I have always, 

 indeed, some "feeling" and also some sense of my "self- 

 existence " ; but what I perceive primarily, directly, and 

 immediately is neither the "feeling" nor the "self-exist- 

 ence," but some concrete actual doing, being, or suffering 

 then experienced. We can, indeed, become distinctly and 

 explicitly aware of either the "feeling" or the "self-exist- 

 ence" by turning back the mind upon itself. But to 

 know that one " has a feeling " or is in a " state," or even 

 that a " feeling exists," is plainly an act by which no one 

 begins to think. It is evidently a secondary act — an act 

 of reflection. No one begins by perceiving his percep- 

 tion a bit more than he begins by expressly adverting to 

 the fact that it is he himself who perceives it. 



Let us suppose two men to be engaged in a fencing 

 match. Each man, while he is parrying, lunging, &c., 

 has his "feelings" or " states," and knows that it is "he" 

 who is carrying on the struggle. Yet it is neither his 

 " mental states" nor the "persistence of his being ^^ which 

 he directly regards, but his concrete activity — what he is 

 doing and what is being done to him. He may, of course, 

 if he chooses, direct his attention either to the feelings 



