62 



NATURE 



[November 19, 1891 



that he cannot at the same time have both two eyes and 

 only one eye, he will, I think, see that his perception is 

 (as mine is) a perception of real incompatibility, and con- 

 sequent positive impossibility. He will not find his mind 

 a mere blank, passively unable to imagine something. 

 He will find that his mind actively asserts its power to 

 judge of the matter as well as what its judgment is, and 

 that the truth is one which positively applies to things, 

 and not merely to his own imaginings. 



Moreover, this objection ignores the difference between 

 intellect and imagination. Yet there are very many 

 things we can conceive of but cannot imagine, as, for 

 example, our " act of sight " or " our own annihilation." 



But it appears to me evident that Mr. Herbert Spencer's 

 " universal postulate " can never be itself an ultimate truth, 

 but must depend upon the law of contradiction. For, sup- 

 posing we had tried to imagine a thing and failed, how 

 could we from that ever be sure we might not at the 

 same time have actually tried and succeeded, if we could 

 not rely upon the law of contradiction ? 



The consequences resulting from any real doubt as to 

 this law we will see later on. 



In the pursuit of science, observation is anterior to 

 experiment ; but in every observation in which we place 

 confidence, and still more in every experiment, a third 

 fundamental truth is necessarily implied : this implied 



truth is THE VALIDITY OF OUR FACULTY OF MEMORY. 



It is plain that it would be impossible for us to be 

 certain about any careful observation or any experiment, 

 if we could not feel confidence in our memory being able 

 to vouch for the fact that we had observed certain pheno- 

 mena and what they were. But what is memory .? 



Evidently we cannot be said to remember anything 

 unless we are conscious that the thing we so remember 

 has been present to our mind on some previous occasion. 

 A mental image might present itself to our imagination 

 a hundred times ; but if at each recurrence it seemed to 

 us something altogether new, and unconnected with the 

 past, we could not be said to remember it. It would 

 rather be an example of extreme forgetfulness than of 

 memory. 



By asserting the trustworthiness of our faculty of 

 memory, I do not, of course, mean that we may not 

 occasionally make mistakes about the past. It is quite 

 certain we may, and do, make such mistakes. But, never- 

 theless, we are all of us certain as to some past events. 

 Probably there is no single person now in this room who 

 is not certain that he was somewhere else before he 

 entered it. Memory informs us — certainly it informs me 

 — as surely concerning some portions of the past, as con- 

 sciousness does concerning some portions of the present. 

 If we could not trust our faculty of memory, the whole 

 of physical science would be, for us, a mere present 

 dream. But there can be no such thing as proof of the 

 trustworthiness of memory, since no argument is possible 

 without trusting to the veracity of memory. It is there- 

 fore a fundamental fact which niust be taken on its own 

 evidence, and from a consideration of the results of any 

 real doubt about it— results I will refer to presently. 



Yet it has been strangely declared, by a leading agnos- 

 tic, that we may trust our memory because we learn its 

 trustworthiness by experience. Surely never was fallacy 

 more obvious ! How could we ever gain experience if 

 we did not trust memory in gaining it t Particular acts 

 of memory may, of course, be confirmed by experience if 

 XhQ faculty of memory be already trusted, but in every 

 such instance it must be confided in. The agnostic re- 

 ferred to has told us in effect that we may place con- 

 fidence in our present memory because in past instances 

 its truth has been experimentally confirmed, while we can 

 only know it has been so confirmed by trusting our present 

 memory ! 



But if we admit the trustworthiness of memory at all, a 

 most important consequence follows— one relating to the 



NO. I 151, VOL. 45] 



distinction between what is subjective and what is 

 objective. 



Every feeling or state of consciousness present to the 

 mind of the subject who possesses it is " subjective," and 

 the whole of such experiences taken together constitute 

 the sphere of subjectivity. Whatever is external to our 

 present consciousness or feelings is for us " objective," 

 and all that is thus external is the region of objectivity. 

 Now memory, inasmuch as it reveals to us part of our 

 own past, reveals to us what is " objective," and so intro- 

 duces us into the realm of objectivity, shows us more or 

 less of objective truth, and carries us into a real world 

 which is beyond the range of our own present feelings. 

 This progress, then, this knowledge of objectivity, is, 

 through memory, implied in every scientific experiment 

 the facts of which we regard as certain. 



But our scientific observations and experiments carry 

 with them yet another implication more important still : 

 this is the certainty of our knowledge of our own 

 CONTINUOUS EXISTENCE. Unless we can be sure that 

 we actually made the observations and experiments, on 

 our having made which we rely for our conclusions, how 

 can those conclusions be confidently relied on by us ? 



This impHcation is so important— ^in my opinion so 

 fundamentally important — that I must crave your per- 

 mission to notice it, later on, at some length. But before 

 considering it, I desire to call your attention to the fact 

 that the propositions thus implied by physical science, 

 run directly counter to a system of thought which is 

 widely current to-day, and which has now and again 

 found expression in this theatre. The popular views I 

 refer to may be conveniently summed up as follows : — 



(i) All our knowledge is merely relative. 



(2) We can know nothing but phenomena. 



(3) We have no supremely certain knowledge but that 

 of our own feelings, and therefore we have none such of 

 our continuous existence. 



(4) We cannot emerge from subjectivity, or attain to 

 real knowledge of anything objective. 



Therefore, either I am very much mistaken, or those 

 who uphold the views I have just summed up are much 

 mistaken. 



It may seem presumptuous on my part to come forward 

 here to night to controvert a system upheld by men of 

 such undoubted ability and so unquestionably competent 

 in science, as are men who uphold the system I oppose. 

 I feel therefore that a few words of personal apology and 

 explanation are due from me. 



For full five-and-thirty years I have been greatly 

 interested in such questions. But when my intellectual 

 life began, it was as a student and disciple of that school 

 with which the names of John Stuart Mill, Alexander 

 Bain, G. H. Lewes, Herbert Spencer, and Prof. Huxley 

 have been successively associated— more or less closely. 

 The works of writers of that school I studied to the best 

 of my ability, and I had the advantage of personal 

 acquaintance with some of the more distinguished of 

 them. Thus, by conversation, I was much better enabled 

 to learn what their system was than I could have learned 

 it by reading only. 



However, by degrees, I became sceptical about the 

 validity of the system I had at first ingenuously adopted, 

 but it took me not a {%^ years to clearly see my way 

 through all the philosophical fallacies— as I now regard 

 them— in which I found myself entangled. I say " see 

 my way through^' for I did not free myself from them by 

 dr Giving back but by pushing forwards—slowly work- 

 ing my way through them and out on the other side. 

 Thete circumstances constitute my apology for appearing 

 before you as I do. I have been a dweller in the countiy 

 which I am willing to aid anyone to explore who may wish 

 to explore it. 



{To be continued.) 



