448 



SCIENCE. 



[N. S. Vol. XV. No. 377. 



where the impassable chasm is, but what 

 chiefly concerns us now is the wide diffu- 

 sion of belief in its reality. 



8. The chasm is said to be betiveen the 

 things I may know, or might know, and 

 something unknowable. 



The chasm cannot be between my mind 

 and anything I know, or may know, or 

 might know if I had the opportunity, be- 

 cause the things I know are in my mind, 

 and I can never know anything except 

 knowledge. So we are told that it is be- 

 tween things that are knowable and some- 

 thing that is not only unknown and un- 

 knowing, but unknowable. 



Believers in the chasm do not all put it 

 in the same place. Some declare that we 

 know nothing but the molecular or elec- 

 trical changes in our ganglion cells. For- 

 getting the existence of their own thoughts, 

 or else dismissing them as mere ' epiphe- 

 nomena,' without significance, they tell us 

 that the chasm is between these physiolog- 

 ical changes and the real world to which 

 we try to refer them. 



We have no immediate knowledge of our 

 own brains, but we do know the thoughts 

 that arise in our minds, and Tyndall tells 

 us the chasm is not between the physiolog- 

 ical changes in our brains and the facts 

 of physics, but between thoughts and the 

 physiological changes in our brains. 



A third, and, on the whole, a more con- 

 sistent notion, is that we know impressions, 

 but can never know the thing impressing, 

 nor the thing impressed, nor whether the 

 thing impressing and the thing impressed 

 are two different kinds of unknowables, or 

 only two unknowables of the same kind. 

 This is Spencer's opinion, as I understand 

 it, and it is the opinion of many scientific 

 men. 



We know phenomena, or appearances, 

 they tell us, but are altogether put off with 

 appearances, and can never know either 

 things or minds as they are in themselves. 



We know the eggs in our minds, and the 

 hens in our minds, but as for knowing 

 eggs as they are in themselves or hens as 

 they are in themselves, that, we are told, 

 is forever out of our reach on the other 

 side of the chasm. We may know the hu- 

 man ovum in our minds and the thinking 

 man in our minds, but the human ovum 

 as it is in itself and the thinking man as 

 he is in himself, are utterly unknowable. 



When the fact that we know the hens in 

 our minds is joined to the notion that our 

 minds are in our heads, we reach the in- 

 teresting, but startling, opinion, that the 

 hens we know are the hens inside our 

 heads. Efforts to escape this strange ad- 

 mission by the assertion that we know only 

 the appearance, and not the reality, of 

 hens in our heads, lead one to suspect that 

 the intellectual chasm may not be a grand 

 canyon after all, but only a common bog 

 in which the wayfarer is the more com- 

 pletely mired by his own struggles. 



He who believes he can never know any- 

 thing as it really is, can never know wheth- 

 er what he thinks he believes or disbelieves 

 is really what he thinks it is, rather than 

 sometlung quite different; so the question 

 whether he can believe or disbelieve any- 

 thing is not without interest, although we 

 need not go into it now. 



9. The chasm is not between the things 

 we know and the things that remain to be 

 known. 



The embryologist is well aware that he 

 cannot hope to find out all there is to 

 learn about hens' eggs, or about his mind, 

 or about anything else; but he attributes 

 this truth to the boundless wealth of na- 

 ture, and not to any inherent weakness in 

 his methods. In this meaning of the 

 words, he has no expectation, and no hope, 

 that he will ever know a hen's egg as it 

 really is; and if the chasm were only be- 

 tween the things he knows and the things 

 he has not yet found out, he would frank- 



