,8,, OBSERVATIONS AND CORRESPONDENCE. 639 



tance for Biology, justifies even more forcibly the charge which has in the pre- 

 ceding remarks been made against InteUectmilism, that it makes no attempt to face 

 the really fundamental problems for which critical Idealism has, whether success- 

 fully or not, at least offered us its solution. We md,y talk of "a principle which 

 is neither a material substance nor a physical force," but philosophy has yet to 

 begin its work. Surely we have a right to ask what do you mean by material 

 and immaterial ? What do you mean by substance ? What is the source of these 

 conceptions ? What is their content ? What is their validity ? And so long as 

 such questions remain unanswered we may well doubt whether the system of 

 Intellectualism does more than ofi'er doubtful dogmas in the place of firm 

 foundations for the sciences. R. J. Ryle. 



The Grammar of Science. 



Allow me to thank Dr. Ryle for drawing attention to a misprint or slip of the 

 pen in my Review (Nat. Scl, vol. i., p. 305) of Professor Pearson's Grammar of 

 Science. "Perceptual conception" is obviously self-contradictory. What I wrote, 

 or intended to write, was " perceptual surface." 



Allow me also to assure Dr. Ryle that (as those who have done me the honour 

 to read what I have written thereon are in a position to know) I do trust implicitly, 

 and without fear or hesitation, in the results of psychological analysis ; that I do 

 not wish to "shelve" (in the sense of neglecting) either physics or psychology, 

 though I do advocate our keeping them on different shelves ; that it is not I who 

 forget " that human experience is none the less real .... if it can be shown 

 that the terms which express that experience owe all their significance to their in- 

 separable association with the nature of our perceptive faculty" ; and that, if I do 

 serve two masters, I have at least the wit to know what service is due to each.' 



C. Lloyd Morgan. 



The Permanence of Oceans and Continents. 

 In Dr. Wallace's paper on "The Permanence of the Great Ocean Basins," 

 published in the August number of Natural Science, p. 418, he mentioned as a 

 reason for bringing forward new arguments in favour of the theory of permanence 

 the circumstance that that theory had been attacked by Mr. Jukes-Browne in "The 

 Building of the British Isles," and by myself in an address to the Geological Society, 

 in 1890. Mr. Jukes-Browne has very justly shown, in his paper on " The Evolution of 

 Oceans and Continents," printed in the September number of this journal, that 

 Dr. Wallace's arguments are directed against views not supported by either of us 

 and now held by but very few, if by any, well-informed geologists. How far such 

 extreme views were advocated in my address, and in what respects that address 

 should be regarded as an attack on the permanence theory, will, I think, be shown by 

 the following extract, taken from the concluding remarks [Proc. Geol.Soc. , 1 8go, p. 107) : — 



"It will thus be seen that while the general permanence of ocean-basins and 

 continental areas cannot be said to be established on anything like firm proof, the 

 general evidence in favour of this view is very strong. But there is no evidence 

 whatever in favour of the extreme view accepted by some physicists and geologists 

 that every ocean-bed now more than 1,000 fathoms deep has always been ocean, 

 and that no part of the continental area has ever been beneath the deep sea." 



I think anyone who reads my address will see that this passage is a fair 

 summary, and that my principal arguments applied, not to the theory of general 

 permanence, but to the view then held by Dr. Wallace and some other naturalists 

 and geologists, that the continental area is limited by the 1,000-fathom line. This 

 view is now admitted to be untenable by Dr. Wallace, and as he concurs in the 

 possibility of ancient land-connections between the three southern continents and 

 the Antarctic land, he concedes every case that I dwelt upon except one, the 

 existence, in Mesozoic times, of land uniting Madagascar and India, to which he does 

 not refer. Under these circumstances, I think anyone reading Dr. Wallace's paper 

 might suppose that the differences between us are much greater than is really the case. 



The three arguments now brought forward by Dr. Wallace, are, as he says^ 

 " altogether inconsistent with any general interchange of oceanic and continental 



