[My Book] will endeavour to establish the principle[s] of reasoning in ... [geology]; and all my geology will come in as illustration of my views of those principles, and as evidence strengthening the system necessarily arising out of the admission of such principles, which... are neither more nor less than that no causes whatever have from the earliest time to which we can look back, to the present, ever acted, but those now acting; and that they never acted with different degrees of energy from that which they now exert.

I long ago suggested the hypothesis, that in the basin of the Thames there are indications of a meeting in the Pleistocene period of a northern and southern fauna.

It was a profound saying of Wilhelm Humboldt, that 'Man is man only by means of speech, but in order to invent speech he must be already man.'

Notwithstanding, therefore, that we have not witnessed of a large continent, yet, as we may predict the future occurrence of such catastrophes, we are authorized to regard them as part of the present order of Nature.

So far from having a materialistic tendency, the supposed introduction into the earth at successive geological periods of life,-sensation,-instinct,-the intelligence of the higher mammalia bordering on reason,-and lastly the improvable reason of Man himself, presents us with a picture of the ever-increasing dominion of mind over matter.

It has long been a fact familiar to geologists, that, both on the east and west coasts of the central part of Scotland, there are lines of raised beaches, containing marine shells of the same species as those now inhabiting the neighbouring sea.

Hitherto, no rival hypothesis has been proposed as a substitute for the doctrine of transmutation; for 'independent creation,' as it is often termed, or the direct intervention of the Supreme Cause, must simply be considered as an avowal that we deem the question to lie beyond the domain of science.