Ixiv INTRODUCTION. 
I reply—Because the facts were little known to geologists: and, perhaps, because they 
little cared about them; for paleontologists who know little of field labour may regard 
nomenclature as of very secondary moment—Because they had not considered the sophism 
by which the Silurian nomenclature had been expanded, or the positive injustice and 
geological untruth which it virtually involved—Lastly, and I believe chiefly, because they 
supposed that I had made some egregious, but unacknowledged blunder; and that I had, 
in consequence, quietly abandoned my whole scheme of classification and nomenclature. 
And well might they believe so, after the audacious liberty taken by Mr Warburton with 
the nomenclature of a paper published in my name in 1843%*. 
It was under this impression (I write advisedly) that the Director of the Govern- 
ment Survey began, and went on with, his great Survey of Wales. “He believed that I 
had abandoned a very good nomenclature,” for reasons known to myself; and that the 
Silurian nomenclature was, therefore, to be regarded as, in fact, acknowledged and esta- 
blished: and hence that the primary object of the Survey was to give meaning to the 
Lower Silurian groups. Be this as it may, the Surveyors did not (as they were logically 
bound to do) keep their nomenclature in abeyance till they had worked out all the 
physical and paleontological subdivisions of the great Cambrian Series. On the contrary, 
assuming the Silurian nomenclature and the new Silurian map as their guide, though by 
their early observations in South Wales they proved that the Llandeilo Flag had been 
put in a false relation to the Upper Cambrian groups, they first reduced it to its right 
place in the general series; then they expanded it upwards through five or six thousand feet 
of strata, and downwards through more than twice as many thousands; and thus they 
elaborated their second division (in conformity with the new Silurian map of 1843), by 
a process which had no reference to the natural succession of physical groups, and with 
a nomenclature which was geographically incongruous and untrue. They did this while 
a truer and more philosophical nomenclature was before them; which, however, they be- 
lieved that I had abandoned. 
* Strange as it may appear, yet is it literally true, that for a period of about seven years I remained in absolute 
ignorance of the fact that Mr Warburton—in the opening paper of the Quarterly Journal of the Geological Society, which 
was published in my name, though never revised by myself during its passage through the press, and studiously kept from 
my revision—had quietly tampered with my nomenclature, and made me perpetrate (quite unconsciously and against plain 
truth and reason) an act of scientific suicide. I haye had a long, and perhaps unreasonable, dislike of premature nomen- 
clature. But it can do no harm, and it may sometimes do good as a means of marshalling our supposed facts together, so 
long as it is used provisionally. But when our provisional nomenclature is assumed as dogmatically fixed and permanent, 
while the critical and fundamental facts assume a new type through the progress of discovery—when our provisional names 
are not so modified as to suit our new facts, but our new facts are so distorted as to suit our first nomenclature; it then 
becomes not merely unsymmetrical and in bad taste, but it becomes a very mischievous hindrance to the cause of truth 
and reason; for it literally compels us to march in fetters. I cared little about nomenclature, and I was ready to modify 
my own in any way compatible with scientific truth. It was not till I found myself excluded from the classification and 
nomenclature of North Wales (though I had, with a near approach to truth of detail, analysed the whole Cambrian Series, 
which assuredly had not been done by any other English geologist) that I began to maintain my own position; and I then 
found that while vindicating myself I was only contending against palpable error, and vindicating those very principles which 
have been the guide of Geologists in every step of real progress; and form the basis of the logic by which geology has 
gradually risen into a symmetrical and secure system of classification and nomenclature. 
