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Piece of chalk
1868
The basis for T.H. Huxley's vivid depiction of the geological history of the Earth.
1868
The basis for T.H. Huxley's vivid depiction of the geological history of the Earth.
What is this wide-spread component of the surface of the earth? and whence did it come? You may think this no very hopeful inquiry… But, in truth, after much deliberation, I have been unable to think of any topic which would so well enable me to lead you to see how solid is the foundation upon which some of the most startling conclusions of physical science rest.
T.H. Huxley, ‘On a Piece of Chalk’ (1868)
‘On a Piece of Chalk’ was a lecture delivered by Thomas Henry Huxley at a meeting of the British Association for the Advancement of Science in Norwich. In it, Huxley meticulously reconstructed the geological history of Britain from his starting point of a piece of chalk, demonstrating the processes of scientific reasoning, as well as a sense of wonder at the workings of nature itself. In doing so, he made a compelling case for the slow evolution of the earth and its inhabitants, rooted firmly in the science available to him – and to anyone who examined it. ‘I assert,’ he said
that the man who should know the true history of the bit of chalk which every carpenter carries about in his breeches-pocket, though ignorant of all other history, is likely, if he will think his knowledge out to its ultimate results, to have a truer, and therefore a better, conception of this wonderful universe, and of man’s relation to it, than the most learned student who is deep-read in the records of humanity and ignorant of those of Nature.
Huxley explained that chalk is composed of remnants of the tiny little skeletons of sea creatures, who long ago lived, died, and sunk to the bottom of the ocean. These deposited layers, and the vastly different makeup of the land that now sits on top of them, could demonstrate the vast age of the earth and the slow, continual processes of change that govern it. Huxley suggested that, on the basis of the evidence available, ‘we have as strong grounds for believing that all the vast area of dry land, at present occupied by the chalk, was once at the bottom of the sea, as we have for any matter of history whatever; while there is no justification for any other belief’. This final line was as key for Huxley as it is for us today: we arrive at theories based upon the evidence available, remaining open to the discovery of new proofs which might lead us to reevaluate our convictions. As both a skilled scientific educator, and the coiner of the term ‘agnostic’ to describe an acceptance of what cannot be proven, Huxley was a vital player in the 19th century humanist tradition, boldly using the increased knowledge available to establish new ways of thinking. He used his lecture’s final lines to state the compelling evidence for a naturalistic view of the world, so central to the humanist position, for:
…in the shifting “without haste, but without rest” of the land and sea, as in the endless variation of the forms assumed by living beings, we have observed nothing but the natural product of the forces originally possessed by the substance of the universe.
Today, the chalk represents both what we now know about the history of the Earth and how we are able to pass that knowledge on to future generations, whether via chalk on a blackboard, pen on paper, word of mouth, or text on screen.
‘Thinking too much about chalk’ | NPR