<P> Uniformitarianism, also known as the Doctrine of Uniformity, refers to the invariance in the principles underpinning science, such as the constancy of causality, or causation, throughout time, but it has also been used to describe invariance of physical laws through time and space . Though an unprovable postulate that cannot be verified using the scientific method, uniformitarianism has been a key first principle of virtually all fields of science . </P> <P> In geology, uniformitarianism has included the gradualistic concept that "the present is the key to the past" (that events occur at the same rate now as they have always done); many geologists now, however, no longer hold to a strict theory of gradualism . Coined by William Whewell, the word was proposed in contrast to catastrophism by British naturalists in the late 18th century, starting with the work of the geologist James Hutton in his many books including Theory of the Earth . Hutton's work was later refined by scientist John Playfair and popularised by geologist Charles Lyell's Principles of Geology in 1830 . Today, Earth's history is considered to have been a slow, gradual process, punctuated by occasional natural catastrophic events . </P>

Uniformitarianism is the assumption that ____
find me the text answering this question