A British geologist born in Scotland (1797-1875 CE). His most important work was The Principles of Geology: An Attempt to Explain the Former Changes of the Earth's Surface by Reference to Causes Now in Operation. Lyell championed the theory of uniformitarianism, which states that the same processes we see on Earth today were active throughout the past and shaped the Earth as we know it, including slow processes like sedimentation. This opposed the leading view at that time, catastrophism, which states that changes to the Earth's surface occur in sudden, discrete events. He also wrote Elements of Geology, which is still considered a seminal work on stratigraphy and paleontology. His third major, though now lesser known, work was The Antiquity of Man, in which he supports Darwin's theories regarding the origins of species. The Lyell Medal is now awarded yearly by the Council of the Geological Society to a significant contemporary geologist. For further information, see our module The Rock Cycle.