ADDRESS. IXXV 



Experiences, but upon oui' -unconscious co-ordination of the luhole ac/grerjate 

 of oitr Experiences, — not on the conclusiveness of any one train of Keasoning, 

 but on the convergence of all our lines of thought towards this one centre. 



Now this " Common Sense," disciphned and enlarged by appropriate culture, 

 becomes one of our most valuable instruments of Scientific inquiiy ; affording 

 in many instances the best, and sometimes the only, basis for a rational con- 

 clusion. Let us take as a typical case, in which no special knowledge is 

 required, what we are accustomed to call the " flint implements " of the 

 Abbeville and Amiens gravel-beds. No logical proof can be adduced that 

 the peculiar shapes of these flints were given to them by Human hands ; but 

 does any unprejudiced person now doubt it ? The evidence of design, to 

 which, after an examination of one or two such specimens, we should only 

 be justified in attaching a probable value, derives an irresistible cogency 

 from accumulation. On the other hand, the rwiprobability that these flints 

 acquired their peculiar shape by accident, becomes to our minds greater 

 and greater as more and more such specimens are found ; until at last this 

 hypothesis, although it cannot be directly disproved, is felt to be almost in- 

 conceivable, except by minds previously " possessed " by the " dominant idea " 

 of the modern origin of Man. And thus what was in the first instance a 

 matter of discussion, has now become one of those " self-evident " propositions, 

 which claim the unhesitating assent of all whose opinion on the subject is 

 entitled to the least weight. 



We proceed upwards, however, from such questions as the Common Sense 

 of Mankind generally is competent to decide, to those in which special know- 

 ledge is required to give value to the judgment ; and thus the interpretation 

 of Nature by the use of that faculty comes to be more and more individual ; 

 things being perfectly " self-evident " to men of special culture, which ordi- 

 nary men, or men whose training has lain in a different direction, do not 

 apprehend as such. Of all departments of Science, Geology seems to me to 

 be the one that most depends on this specially-trained "Common Sense;" 

 which brings as it were into one focus the light afforded by a great 

 variety of studies, — Physical and Chemical, Geographical and Biological; 

 and throws it on the pages of that Great Stone Book, on which the past 

 history of our Globe is recorded. And whilst Astronomy is of all Sciences 

 that which may be considered as most nearly representing Nature as she 

 really is. Geology is that which most completely represents her as seen 

 through the medium of the interpreting mind ; the meaning of the phenomena 

 that constitute its data being in almost every instance open to question, 

 and the judgments passed upon the same facts being often different according 

 to the qualifications of the several judges. No one who has even a general 

 acquaintance with the history of this department of Science, can fail to see 

 that the Geology of each epoch has been the reflection of the Minds by which 

 its study was then directed ; and that its true progress dates from the time 

 when that " Common Sense " method of interpretation came to be generally 

 adopted, which consists in seeking the explanation of past changes in the 

 Forces at present in operation, instead of invoking the aid of extraordinary 

 and mysterious agencies, as the older Geologists were wont to do, whenever 

 they wanted — like the Ptolemaic Astronomers — " to save appearances." The 

 whole tendency of the ever-widening range of modern Geological inquiry 

 has been to show how little reliance can be placed upon the so-called 

 " Laws " of Stratigraphical and Palseontological Succession, and how much 

 allowance has to be made for local conditions. So that while the Astro- 

 nomer is constantly enabled to point to the fulfilment of his predictions as an. 



