To Hutton, rocks were ‘God’s books wrote upon by God’s own finger’.
He consulted the testimony of rocks tirelessly and methodically. His extensive travels in Britain always had a geological purpose. Over a thirty year period of arduous travel and field observation, he was able to gain a detailed and remarkable knowledge of rocks and their distribution in the British Isles and so to formulate an understanding of its geological make-up. This was supplemented by extensive reading of explorers accounts of other countries and continents. Playfair records how Hutton ‘never ceased to study the natural history of the globe, with a view to ascertaining the changes that have taken place on its surface and of discovering the causes by which they have been produced...’. He was driven in his sense of purpose and great hunger for knowledge such that he describes himself in a letter to George Maxwell-Clerk ‘Lord, pity the arse that’s clagged to a head that will hunt stones’ …’I begin to be tired of speaking to stones and long for a fresh bit of mortality to make sauce for them’.