84 



NATURE 



[November 26, 1891 



he is experiencing or to his underlying continuous per- 

 sonality. Should he do so, however, a hit from his 

 adversary's foil will be a probable result. 



But to become aware that one has any definite feeling 

 is a reflex act at least as secondary and posterior as it is 

 to become aware of the " self" which has the feeling. I 

 say " at least" but I believe that of the two perceptions 

 (i) of " feelings," and (2) of " self," it is the " self" which 

 is the more prominently given in our primary, direct 

 cognitions. 



I believe that a more laborious act of mental digging is 

 requisite to bring explicitly to light the implicit mental 

 state, than to bring forward explicitly the implicit " self- 

 existence." Men continually and promptly advert to the 

 fact that actions and sufferings are their own, but do not 

 by any means so continually and promptly advert to 

 the fact that the feelings they experience are " existing 

 feelings." 



Therefore I am convinced that one of the greatest and 

 most fundamental errors of our day is the mistake of 

 supposing that we can know our "mental states" or 

 " feelings," more certainly and directly than we can 

 know the continuously existing self which has those 

 feelings. 



Our perception of our continuous existence also in- 

 volves the validity of our faculty of memory, which is 

 implied in this way, as well as in every scientific ex- 

 periment we may perform. For we cannot obviously 

 have a reflex perception either of our "feelings" or our 

 " self-existence," without trusting our memory as to the 

 past ; since, however rapid our mental processes may 

 be, no mental act takes place without occupying some 

 period of time, and, indeed, nervous action is not ex- 

 tremely rapid. In knowing, therefore, such facts by a 

 reflex act, we know by memory what is already past. 

 Thus our certainty as to our own continuous existence 

 necessarily carries with it a certainty as to our faculty of 

 memory. Therefore, the mental idiocy of absolute scep- 

 ticism is the penalty that has to be paid for any real 

 doubt about our own existence or the trustworthiness of 

 the faculty of memory, for all our power of reposing con- 

 fidence in our observations, experiments, or reasonings, 

 would, in that case, be logically at an end. On the 

 other hand, the validity of our faculty of memory esta- 

 blishes once for all (as we have seen) the fact that we 

 can transcend our present consciousness and know real 

 objective truth. 



Let us now see the consequences of the denial, or real 

 doubt of the second implication of science — the " law of 

 contradiction." Without it we can be certain of nothing, 

 and it therefore lands us in absolute scepticism. And if 

 we would rise from that intellectual paralysis we must 

 accept that dictum as it presents itself to our minds ; and 

 the dictum presents itself to my mind, not as a law of 

 thought only, but a law of things. It affirms, for example, 

 that no creature anywhere or 1 any when can at the same 

 time be both bisected and entire. 



An amusing instance of the way in which very dis- 

 tinguished men may be misled as to the question of our 

 power of perceiving necessary truth is off"ered by an 

 imaginary case which has been put forward by Prof. 

 Clifford and Prof. Helmholtz. Their object in advancing 

 it was to show, by an example, how truths which appear 

 necessary to us are not objectively necessary. But the 

 result appears to me to show the direct contradictory of 

 what they intended. Their intention evidently was to 

 support the proposition that we can know " no truths to 

 he absolutely necessary" and the result is to show that, 

 even according to them, " some truths are absolutely 

 necessary." The necessary truths they propose to con- 

 trovert are that " a straight line is the shortest line 

 between two points," and that " two straight lines cannot 

 inclose a space." 



For this purpose, curious creatures, possessing length 



NO. IT 52, VOL. 45] 



and breadth but no thickness, were supposed, by them, 

 to be living on a sphere with the surface of which their 

 bodies would coincide. They were imagined to have 

 experience of length and breadth in curves, but none of 

 height and depth, or of any straight lines. To such crea- 

 tures, it was said, our geometrical necessary truths would 

 not appear " truths " at all. A straight line for them 

 would not be the shortest line, while two parallel lines 

 prolonged would inclose a space. 



To this imaginary objection I reply as follows : — 

 " Beings so extraordinarily defective might, Ukely enough, 

 be unable to perceive geometrical truths which to less 

 defective creatures — such as ourselves — are perfectly 

 clear. Nevertheless, if they could conceive of such things 

 at all, as those we denote by the terms 'straight lines' 

 and ' parallel lines,' then there is nothing to show that 

 they could not also perceive those same necessary truths 

 concerning them which are evident to us." 



It is strange that the very men who make this fanciful 

 objection, actually show, by the way they make it, that 

 they themselves perceive the necessary truth of those 

 geometrical relations the necessity of which they verbally 

 deny. For how, otherwise, could they affirm what would 

 or would not be the necessary results attending such 

 imaginary conditions.? How could they confidently 

 declare what perceptions such conditions would cer- 

 tainly produce, unless they were themselves convinced 

 of the validity of the laws regulating the experiences of 

 such beings ? If they affirm, as they do, that they per- 

 ceive what must be the truth in their supposed case, 

 they thereby implicitly assert the existence of some abso- 

 lutely necessary truths, or else their own argument itself 

 falls to the ground. 



But this same implication of science, respecting the 

 objective absolute validity of the law of contradiction, 

 also refutes that popular system of philosophy which 

 declares that all our knowledge is merely relative, and 

 that we can know nothing as it really exists independ- 

 ently of our knowledge of it, the system which proclaims 

 the " relativity of knowledge.'" 



Of course anything which is "known to us" cannot at 

 the same time be " unknown to us" and so far as this, 

 our knowledge may be said to affect the things we know. 

 But this is trivial. Our "knowing" or " not-knowing " 

 any object is — apart from some act of ours which results 

 from our knowledge — a mere accident of that body's 

 existence, which is not otherwise affected thereby. 



Again, as I before remarked, nothing, so far as we 

 know, exists by itself, and unrelated to any other thing. 

 To say, therefore, that "all our knowledge is relative" 

 might only mean that knowledge concords with objective 

 reality. But this is by no means what the upholders of 

 the " relativity of knowledge " intend to signify. They 

 deny the objective validity, the actual correspondence 

 with reality, of any of our perceptions or convictions — 

 even, as Mr. Herbert Spencer tells us, our cognition of 

 " difference." 



Every system of knowledge, however, must start with 

 the assumption, implied or expressed, that something is 

 true. By the teachers of the doctrine of the " relativity 

 of knowledge " it is evidently taught that the doctrine of 

 the relativity of knowledge is true. But if we cannot 

 know that anything corresponds with external reality, if 

 nothing we can assert has more than a relative or phe- 

 nomenal value, then this character must also appertain to 

 the doctrine of the " relativity of knowledge." Either 

 this system of philosophy is merely relative or pheno- 

 menal, and cannot be known to be true, or else it is abso- 

 lutely true, and can be known so to be. But it must be 

 merely relative and phenomenal, if everything known by 

 man is such. Its value, then, can be only relative and 

 phenomenal, therefore it cannot be known to correspond 

 with external reality, and cannot be asserted to be true ; 

 and anybody who asserts that we can know it to be true. 



