Theory of the Earth is a publication by James Hutton which laid the foundations for geology.

[5][6] Hutton recognized that rocks record the evidence of the past action of processes which still operate today.

He also anticipated natural selection, as follows: "Those which depart most from the best adapted constitution, will be the most liable to perish, while, on the other hand, those organised bodies, which most approach to the best constitution for the present circumstances, will be best adapted to continue, in preserving themselves and multiplying the individuals of their race".

[8] They were not taken seriously until 1802, when Edinburgh University mathematics professor John Playfair restated Hutton's geological ideas in clearer, much simpler English.

[9] Charles Lyell in the 1830s popularised the idea of an infinitely repeating cycle (of the erosion of rocks and the building up of sediment).